id revision location occurrence kind text registry scope state_after support disposition C00001 base docs/mysql/01-basics/begin-commit-rollback.md:1 docs/mysql/01-basics/begin-commit-rollback.md## BEGIN, COMMIT, ROLLBACK/line@1 lesson-unit # BEGIN, COMMIT, ROLLBACK M1 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Retained with scoped support; current occurrence docs/mysql/01-basics/begin-commit-rollback.md## BEGIN, COMMIT, ROLLBACK/line@1 at docs/mysql/01-basics/begin-commit-rollback.md:1 C00002 base docs/mysql/01-basics/begin-commit-rollback.md:3 docs/mysql/01-basics/begin-commit-rollback.md## BEGIN, COMMIT, ROLLBACK/paragraph@3 lesson-unit MySQL runs with `autocommit = 1` by default: every statement outside an explicit transaction is its own transaction, committed the instant it finishes. `BEGIN` (an alias for `START TRANSACTION`) suspends that until you `COMMIT` or `ROLLBACK`. M1 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/removed; corrected current source in docs/mysql/01-basics/begin-commit-rollback.md, see semantic decisions A1-A10 C00003 base docs/mysql/01-basics/begin-commit-rollback.md:7 docs/mysql/01-basics/begin-commit-rollback.md### Autocommit and visibility/line@7 lesson-unit ## Autocommit and visibility M1 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Retained with scoped support; current occurrence docs/mysql/01-basics/begin-commit-rollback.md### Autocommit and visibility/line@10 at docs/mysql/01-basics/begin-commit-rollback.md:10 C00004 base docs/mysql/01-basics/begin-commit-rollback.md:9 docs/mysql/01-basics/begin-commit-rollback.md### Autocommit and visibility/line@9 lesson-unit M1 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Retained with scoped support; current occurrence docs/mysql/01-basics/begin-commit-rollback.md### Autocommit and visibility/line@17 at docs/mysql/01-basics/begin-commit-rollback.md:17 C00005 base docs/mysql/01-basics/begin-commit-rollback.md:11 docs/mysql/01-basics/begin-commit-rollback.md### An error does NOT abort the transaction/line@11 lesson-unit ## An error does NOT abort the transaction M1 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/removed; corrected current source in docs/mysql/01-basics/begin-commit-rollback.md, see semantic decisions A1-A10 C00006 base docs/mysql/01-basics/begin-commit-rollback.md:13 docs/mysql/01-basics/begin-commit-rollback.md### An error does NOT abort the transaction/paragraph@13 lesson-unit Here MySQL and PostgreSQL part ways completely. In PostgreSQL, any error aborts the whole transaction: every further statement is refused with `25P02` until you roll back. MySQL rolls back only the failed statement and carries on as if nothing happened: M1 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/removed; corrected current source in docs/mysql/01-basics/begin-commit-rollback.md, see semantic decisions A1-A10 C00007 base docs/mysql/01-basics/begin-commit-rollback.md:17 docs/mysql/01-basics/begin-commit-rollback.md### An error does NOT abort the transaction/line@17 lesson-unit M1 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Retained with scoped support; current occurrence docs/mysql/01-basics/begin-commit-rollback.md### Duplicate-key error without IGNORE preserves the transaction {#an-error-does-not-abort-the-transaction}/line@26 at docs/mysql/01-basics/begin-commit-rollback.md:26 C00008 base docs/mysql/01-basics/begin-commit-rollback.md:19 docs/mysql/01-basics/begin-commit-rollback.md### An error does NOT abort the transaction/paragraph@19 lesson-unit "This is convenient, and dangerous: application code that assumes ""an error means nothing committed"" is wrong on MySQL. If your error handler doesn't explicitly `ROLLBACK`, every statement that succeeded before *and after* the error will commit." M1 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/removed; corrected current source in docs/mysql/01-basics/begin-commit-rollback.md, see semantic decisions A1-A10 C00009 base docs/mysql/01-basics/begin-commit-rollback.md:23 docs/mysql/01-basics/begin-commit-rollback.md### An error does NOT abort the transaction/paragraph@23 lesson-unit Without `BEGIN`, every statement commits on its own, so there's nothing to roll back a moment later; wrap the work in a transaction and your changes stay invisible to others until `COMMIT`, with [chapter 2](/mysql/02-isolation/snapshots-and-the-four-levels) covering the exact visibility rules. After an error the transaction is still alive and only the failed statement was undone, so decide explicitly whether to retry that statement or `ROLLBACK` everything; [the same lesson for PostgreSQL](/postgres/01-basics/begin-commit-rollback) proves the opposite behavior. And watch for statements that [commit implicitly](https://dev.mysql.com/doc/refman/8.4/en/implicit-commit.html): DDL like `ALTER TABLE` or `CREATE INDEX` commits your open transaction before it runs. M1 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/removed; corrected current source in docs/mysql/01-basics/begin-commit-rollback.md, see semantic decisions A1-A10 C00010 base docs/mysql/01-basics/begin-commit-rollback.md:33 docs/mysql/01-basics/begin-commit-rollback.md### Further reading/line@33 lesson-unit ## Further reading M1 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Retained with scoped support; current occurrence docs/mysql/01-basics/begin-commit-rollback.md### Further reading/line@60 at docs/mysql/01-basics/begin-commit-rollback.md:60 C00011 base docs/mysql/01-basics/begin-commit-rollback.md:35 docs/mysql/01-basics/begin-commit-rollback.md### Further reading/paragraph@35 lesson-unit - [MySQL docs: autocommit, Commit, and Rollback](https://dev.mysql.com/doc/refman/8.4/en/innodb-autocommit-commit-rollback.html) - [MySQL docs: Statements That Cause an Implicit Commit](https://dev.mysql.com/doc/refman/8.4/en/implicit-commit.html) - [The same lesson on PostgreSQL](/postgres/01-basics/begin-commit-rollback) M1 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/removed; corrected current source in docs/mysql/01-basics/begin-commit-rollback.md, see semantic decisions A1-A10 C00012 base docs/mysql/01-basics/savepoints.md:1 docs/mysql/01-basics/savepoints.md## Savepoints/line@1 lesson-unit # Savepoints M2 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Retained with scoped support; current occurrence docs/mysql/01-basics/savepoints.md## Savepoints/line@1 at docs/mysql/01-basics/savepoints.md:1 C00013 base docs/mysql/01-basics/savepoints.md:3 docs/mysql/01-basics/savepoints.md## Savepoints/paragraph@3 lesson-unit A savepoint is a named bookmark inside a transaction: `ROLLBACK TO SAVEPOINT` rewinds the transaction's work back to it without giving up the transaction itself. M2 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/removed; corrected current source in docs/mysql/01-basics/savepoints.md, see semantic decisions A1-A10 C00014 base docs/mysql/01-basics/savepoints.md:6 docs/mysql/01-basics/savepoints.md## Savepoints/paragraph@6 lesson-unit In PostgreSQL, savepoints are how you *recover from errors* mid-transaction. MySQL [doesn't abort transactions on error](/mysql/01-basics/begin-commit-rollback), so you rarely need them for that. Their job here is to discard a multi-statement branch in one go. M2 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/removed; corrected current source in docs/mysql/01-basics/savepoints.md, see semantic decisions A1-A10 C00015 base docs/mysql/01-basics/savepoints.md:10 docs/mysql/01-basics/savepoints.md### Discard a risky branch/line@10 lesson-unit ## Discard a risky branch M2 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Retained with scoped support; current occurrence docs/mysql/01-basics/savepoints.md### Discard a risky branch/line@8 at docs/mysql/01-basics/savepoints.md:8 C00016 base docs/mysql/01-basics/savepoints.md:12 docs/mysql/01-basics/savepoints.md### Discard a risky branch/paragraph@12 lesson-unit The risky part of the transaction made real progress before failing. A single `ROLLBACK TO SAVEPOINT` undoes all of it, including the statements that succeeded: M2 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/removed; corrected current source in docs/mysql/01-basics/savepoints.md, see semantic decisions A1-A10 C00017 base docs/mysql/01-basics/savepoints.md:15 docs/mysql/01-basics/savepoints.md### Discard a risky branch/line@15 lesson-unit M2 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Retained with scoped support; current occurrence docs/mysql/01-basics/savepoints.md### Discard a risky branch/line@14 at docs/mysql/01-basics/savepoints.md:14 C00018 base docs/mysql/01-basics/savepoints.md:17 docs/mysql/01-basics/savepoints.md### Nesting and RELEASE/line@17 lesson-unit ## Nesting and RELEASE M2 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Retained with scoped support; current occurrence docs/mysql/01-basics/savepoints.md### Nesting and RELEASE/line@16 at docs/mysql/01-basics/savepoints.md:16 C00019 base docs/mysql/01-basics/savepoints.md:19 docs/mysql/01-basics/savepoints.md### Nesting and RELEASE/line@19 lesson-unit M2 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Retained with scoped support; current occurrence docs/mysql/01-basics/savepoints.md### Nesting and RELEASE/line@22 at docs/mysql/01-basics/savepoints.md:22 C00020 base docs/mysql/01-basics/savepoints.md:21 docs/mysql/01-basics/savepoints.md### Nesting and RELEASE/paragraph@21 lesson-unit `ROLLBACK TO SAVEPOINT` undoes the data changes made after the savepoint but keeps the transaction (and the locks it took before the savepoint) alive. Roll back to an outer savepoint and the inner ones vanish with it, so reaching for one afterward fails with errno `1305`. `RELEASE SAVEPOINT` forgets a bookmark without undoing anything, and every savepoint disappears on `COMMIT` or a full `ROLLBACK`. M2 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/removed; corrected current source in docs/mysql/01-basics/savepoints.md, see semantic decisions A1-A10 C00021 base docs/mysql/01-basics/savepoints.md:27 docs/mysql/01-basics/savepoints.md### Further reading/line@27 lesson-unit ## Further reading M2 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Retained with scoped support; current occurrence docs/mysql/01-basics/savepoints.md### Further reading/line@35 at docs/mysql/01-basics/savepoints.md:35 C00022 base docs/mysql/01-basics/savepoints.md:29 docs/mysql/01-basics/savepoints.md### Further reading/paragraph@29 lesson-unit - [MySQL docs: SAVEPOINT, ROLLBACK TO SAVEPOINT, and RELEASE SAVEPOINT](https://dev.mysql.com/doc/refman/8.4/en/savepoint.html) - [The same lesson on PostgreSQL](/postgres/01-basics/savepoints) M2 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/removed; corrected current source in docs/mysql/01-basics/savepoints.md, see semantic decisions A1-A10 C00023 base docs/mysql/01-basics/what-is-a-transaction.md:1 docs/mysql/01-basics/what-is-a-transaction.md## What is a transaction?/line@1 lesson-unit # What is a transaction? M3 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Retained with scoped support; current occurrence docs/mysql/01-basics/what-is-a-transaction.md## What is a transaction?/line@1 at docs/mysql/01-basics/what-is-a-transaction.md:1 C00024 base docs/mysql/01-basics/what-is-a-transaction.md:3 docs/mysql/01-basics/what-is-a-transaction.md## What is a transaction?/paragraph@3 lesson-unit A transaction groups several statements into one unit of work that either happens completely or not at all. The engine-neutral theory, ACID and what each letter promises, lives in [Concepts: what is a transaction?](/concepts/what-is-a-transaction). This page is MySQL keeping the promise, with one caveat PostgreSQL doesn't have. M3 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/removed; corrected current source in docs/mysql/01-basics/what-is-a-transaction.md, see semantic decisions A1-A10 C00025 base docs/mysql/01-basics/what-is-a-transaction.md:8 docs/mysql/01-basics/what-is-a-transaction.md## What is a transaction?/line@8 lesson-unit ::: tip How to read the demos M3 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Retained with scoped support; current occurrence docs/mysql/01-basics/what-is-a-transaction.md## What is a transaction?/line@14 at docs/mysql/01-basics/what-is-a-transaction.md:14 C00026 base docs/mysql/01-basics/what-is-a-transaction.md:9 docs/mysql/01-basics/what-is-a-transaction.md## What is a transaction?/paragraph@9 lesson-unit Each lesson shows a transcript generated from an actual run of the scenario: plain SQL, color-coded per session (`A`, `B`, … are separate MySQL connections). How the transcripts are produced and verified is explained in [What this is](/about/methodology) M3 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/removed; corrected current source in docs/mysql/01-basics/what-is-a-transaction.md, see semantic decisions A1-A10 C00027 base docs/mysql/01-basics/what-is-a-transaction.md:12 docs/mysql/01-basics/what-is-a-transaction.md## What is a transaction?/line@12 lesson-unit ::: M3 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Retained with scoped support; current occurrence docs/mysql/01-basics/what-is-a-transaction.md## What is a transaction?/line@19 at docs/mysql/01-basics/what-is-a-transaction.md:19 C00028 base docs/mysql/01-basics/what-is-a-transaction.md:14 docs/mysql/01-basics/what-is-a-transaction.md## What is a transaction?/paragraph@14 lesson-unit The caveat: all of this applies to InnoDB, MySQL's default storage engine. Tables on other engines (e.g. `MyISAM`) are not transactional at all: their writes commit instantly, always. M3 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/removed; corrected current source in docs/mysql/01-basics/what-is-a-transaction.md, see semantic decisions A1-A10 C00029 base docs/mysql/01-basics/what-is-a-transaction.md:18 docs/mysql/01-basics/what-is-a-transaction.md### Atomicity, demonstrated/line@18 lesson-unit ## Atomicity, demonstrated M3 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Retained with scoped support; current occurrence docs/mysql/01-basics/what-is-a-transaction.md### Atomicity, demonstrated/line@21 at docs/mysql/01-basics/what-is-a-transaction.md:21 C00030 base docs/mysql/01-basics/what-is-a-transaction.md:20 docs/mysql/01-basics/what-is-a-transaction.md### Atomicity, demonstrated/paragraph@20 lesson-unit Session A transfers 150 from alice (who has only 100) to bob. The credit to bob *succeeds*; the debit from alice violates a `CHECK` constraint. Watch what happens to bob's already-successful credit: M3 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/removed; corrected current source in docs/mysql/01-basics/what-is-a-transaction.md, see semantic decisions A1-A10 C00031 base docs/mysql/01-basics/what-is-a-transaction.md:24 docs/mysql/01-basics/what-is-a-transaction.md### Atomicity, demonstrated/line@24 lesson-unit M3 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Retained with scoped support; current occurrence docs/mysql/01-basics/what-is-a-transaction.md### Atomicity, demonstrated/line@28 at docs/mysql/01-basics/what-is-a-transaction.md:28 C00032 base docs/mysql/01-basics/what-is-a-transaction.md:26 docs/mysql/01-basics/what-is-a-transaction.md### Atomicity, demonstrated/paragraph@26 lesson-unit Two things to carry forward. Unlike PostgreSQL, a failed statement doesn't doom a MySQL transaction: you may roll back, but you're not forced to, as the next lesson [proves](/mysql/01-basics/begin-commit-rollback). And other sessions never saw an intermediate state: B read bob's balance mid-transfer and got the old value, which is exactly what [isolation levels](/mysql/02-isolation/snapshots-and-the-four-levels) govern. M3 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/removed; corrected current source in docs/mysql/01-basics/what-is-a-transaction.md, see semantic decisions A1-A10 C00033 base docs/mysql/01-basics/what-is-a-transaction.md:32 docs/mysql/01-basics/what-is-a-transaction.md### Further reading/line@32 lesson-unit ## Further reading M3 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Retained with scoped support; current occurrence docs/mysql/01-basics/what-is-a-transaction.md### Further reading/line@36 at docs/mysql/01-basics/what-is-a-transaction.md:36 C00034 base docs/mysql/01-basics/what-is-a-transaction.md:34 docs/mysql/01-basics/what-is-a-transaction.md### Further reading/paragraph@34 lesson-unit - [MySQL docs: START TRANSACTION, COMMIT, and ROLLBACK Statements](https://dev.mysql.com/doc/refman/8.4/en/commit.html) - [MySQL docs: InnoDB and the ACID Model](https://dev.mysql.com/doc/refman/8.4/en/mysql-acid.html) - [The same lesson on PostgreSQL](/postgres/01-basics/what-is-a-transaction) M3 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/removed; corrected current source in docs/mysql/01-basics/what-is-a-transaction.md, see semantic decisions A1-A10 C00035 base docs/mysql/02-isolation/anomaly-catalog.md:1 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/line@1 lesson-unit # The anomaly catalog M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Retained with scoped support; current occurrence docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/line@1 at docs/mysql/02-isolation/anomaly-catalog.md:1 C00036 base docs/mysql/02-isolation/anomaly-catalog.md:3 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/paragraph@3 lesson-unit What each MySQL isolation level does about every named anomaly, and the proof. The anomalies themselves (definitions, diagrams, and where the G-codes come from) live in [Concepts: the anomaly catalog](/concepts/isolation-anomalies); this page is MySQL's answer sheet, covering every case [Hermitage](https://github.com/ept/hermitage) tests, including the rows where MySQL's answer differs from PostgreSQL's. M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/removed; corrected current source in docs/mysql/02-isolation/anomaly-catalog.md, see semantic decisions A1-A10 C00037 base docs/mysql/02-isolation/anomaly-catalog.md:9 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/paragraph@9 lesson-unit The short version: on MySQL, [isolation levels protect reads, not read-modify-write cycles](#the-mysql-specific-pattern), so the ⚠️ cells in the bottom half of this table get fixed with locks or SQL arithmetic rather than the isolation knob. The REPEATABLE READ default [still loses updates](/mysql/02-isolation/lost-update#repeatable-read-does-not-save-you) and [current reads see phantoms](/mysql/02-isolation/repeatable-read#current-reads-punch-holes-in-the-snapshot), while SERIALIZABLE closes the rest with locks, so plan to [retry on `1213`](#error-codes-to-retry-on). M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/removed; corrected current source in docs/mysql/02-isolation/anomaly-catalog.md, see semantic decisions A1-A10 C00038 base docs/mysql/02-isolation/anomaly-catalog.md:18 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@18.cell[0] catalog-cell Code M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Retained with scoped support; current occurrence docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@15.cell[0] at docs/mysql/02-isolation/anomaly-catalog.md:15 C00039 base docs/mysql/02-isolation/anomaly-catalog.md:18 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@18.cell[1] catalog-cell Anomaly M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/reorganized by row subject and evidence boundary; current occurrence docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@15.cell[1] at docs/mysql/02-isolation/anomaly-catalog.md:15 C00040 base docs/mysql/02-isolation/anomaly-catalog.md:18 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@18.cell[2] catalog-cell READ UNCOMMITTED M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Retained with scoped support; current occurrence docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@15.cell[2] at docs/mysql/02-isolation/anomaly-catalog.md:15 C00041 base docs/mysql/02-isolation/anomaly-catalog.md:18 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@18.cell[3] catalog-cell READ COMMITTED M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Retained with scoped support; current occurrence docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@15.cell[3] at docs/mysql/02-isolation/anomaly-catalog.md:15 C00042 base docs/mysql/02-isolation/anomaly-catalog.md:18 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@18.cell[4] catalog-cell REPEATABLE READ *(default)* M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/reorganized by row subject and evidence boundary; current occurrence docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@15.cell[4] at docs/mysql/02-isolation/anomaly-catalog.md:15 C02306 base docs/mysql/02-isolation/anomaly-catalog.md:18 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@18.cell[5] catalog-cell SERIALIZABLE M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Retained with scoped support; current occurrence docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@15.cell[5] at docs/mysql/02-isolation/anomaly-catalog.md:15 C00043 base docs/mysql/02-isolation/anomaly-catalog.md:19 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@19.cell[0] catalog-cell --- M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Retained with scoped support; current occurrence docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@16.cell[0] at docs/mysql/02-isolation/anomaly-catalog.md:16 C00044 base docs/mysql/02-isolation/anomaly-catalog.md:19 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@19.cell[1] catalog-cell --- M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Retained with scoped support; current occurrence docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@16.cell[1] at docs/mysql/02-isolation/anomaly-catalog.md:16 C00045 base docs/mysql/02-isolation/anomaly-catalog.md:19 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@19.cell[2] catalog-cell --- M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Retained with scoped support; current occurrence docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@16.cell[2] at docs/mysql/02-isolation/anomaly-catalog.md:16 C00046 base docs/mysql/02-isolation/anomaly-catalog.md:19 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@19.cell[3] catalog-cell --- M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Retained with scoped support; current occurrence docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@16.cell[3] at docs/mysql/02-isolation/anomaly-catalog.md:16 C00047 base docs/mysql/02-isolation/anomaly-catalog.md:19 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@19.cell[4] catalog-cell --- M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Retained with scoped support; current occurrence docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@16.cell[4] at docs/mysql/02-isolation/anomaly-catalog.md:16 C02307 base docs/mysql/02-isolation/anomaly-catalog.md:19 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@19.cell[5] catalog-cell --- M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Retained with scoped support; current occurrence docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@16.cell[5] at docs/mysql/02-isolation/anomaly-catalog.md:16 C00048 base docs/mysql/02-isolation/anomaly-catalog.md:20 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@20.cell[0] catalog-cell G0 M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Retained with scoped support; current occurrence docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@17.cell[0] at docs/mysql/02-isolation/anomaly-catalog.md:17 C00049 base docs/mysql/02-isolation/anomaly-catalog.md:20 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@20.cell[1] catalog-cell **Dirty write** M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/reorganized by row subject and evidence boundary; current occurrence docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@17.cell[1] at docs/mysql/02-isolation/anomaly-catalog.md:17 C00050 base docs/mysql/02-isolation/anomaly-catalog.md:20 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@20.cell[2] catalog-cell ✅ impossible, [proof](#dirty-writes-g0) M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/reorganized by row subject and evidence boundary; current occurrence docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@17.cell[2] at docs/mysql/02-isolation/anomaly-catalog.md:17 C00051 base docs/mysql/02-isolation/anomaly-catalog.md:20 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@20.cell[3] catalog-cell ✅ M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/reorganized by row subject and evidence boundary; current occurrence docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@17.cell[3] at docs/mysql/02-isolation/anomaly-catalog.md:17 C00052 base docs/mysql/02-isolation/anomaly-catalog.md:20 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@20.cell[4] catalog-cell ✅ M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/reorganized by row subject and evidence boundary; current occurrence docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@17.cell[4] at docs/mysql/02-isolation/anomaly-catalog.md:17 C02308 base docs/mysql/02-isolation/anomaly-catalog.md:20 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@20.cell[5] catalog-cell ✅ M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/reorganized by row subject and evidence boundary; current occurrence docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@17.cell[5] at docs/mysql/02-isolation/anomaly-catalog.md:17 C00053 base docs/mysql/02-isolation/anomaly-catalog.md:21 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@21.cell[0] catalog-cell G1a M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Retained with scoped support; current occurrence docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@18.cell[0] at docs/mysql/02-isolation/anomaly-catalog.md:18 C00054 base docs/mysql/02-isolation/anomaly-catalog.md:21 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@21.cell[1] catalog-cell **Dirty read** (aborted read) M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/reorganized by row subject and evidence boundary; current occurrence docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@18.cell[1] at docs/mysql/02-isolation/anomaly-catalog.md:18 C00055 base docs/mysql/02-isolation/anomaly-catalog.md:21 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@21.cell[2] catalog-cell ⚠️ [happens](/mysql/02-isolation/snapshots-and-the-four-levels#read-uncommitted-means-it) M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/reorganized by row subject and evidence boundary; current occurrence docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@18.cell[2] at docs/mysql/02-isolation/anomaly-catalog.md:18 C00056 base docs/mysql/02-isolation/anomaly-catalog.md:21 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@21.cell[3] catalog-cell ✅ impossible M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/reorganized by row subject and evidence boundary; current occurrence docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@18.cell[3] at docs/mysql/02-isolation/anomaly-catalog.md:18 C00057 base docs/mysql/02-isolation/anomaly-catalog.md:21 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@21.cell[4] catalog-cell ✅ M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/reorganized by row subject and evidence boundary; current occurrence docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@18.cell[4] at docs/mysql/02-isolation/anomaly-catalog.md:18 C02309 base docs/mysql/02-isolation/anomaly-catalog.md:21 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@21.cell[5] catalog-cell ✅ M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/reorganized by row subject and evidence boundary; current occurrence docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@18.cell[5] at docs/mysql/02-isolation/anomaly-catalog.md:18 C00058 base docs/mysql/02-isolation/anomaly-catalog.md:22 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@22.cell[0] catalog-cell G1b M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Retained with scoped support; current occurrence docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@19.cell[0] at docs/mysql/02-isolation/anomaly-catalog.md:19 C00059 base docs/mysql/02-isolation/anomaly-catalog.md:22 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@22.cell[1] catalog-cell **Intermediate read** M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/reorganized by row subject and evidence boundary; current occurrence docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@19.cell[1] at docs/mysql/02-isolation/anomaly-catalog.md:19 C00060 base docs/mysql/02-isolation/anomaly-catalog.md:22 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@22.cell[2] catalog-cell ⚠️ [happens](#intermediate-reads-g1b) M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/reorganized by row subject and evidence boundary; current occurrence docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@19.cell[2] at docs/mysql/02-isolation/anomaly-catalog.md:19 C00061 base docs/mysql/02-isolation/anomaly-catalog.md:22 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@22.cell[3] catalog-cell ✅ impossible, [proof](#intermediate-reads-g1b) M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/reorganized by row subject and evidence boundary; current occurrence docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@19.cell[3] at docs/mysql/02-isolation/anomaly-catalog.md:19 C00062 base docs/mysql/02-isolation/anomaly-catalog.md:22 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@22.cell[4] catalog-cell ✅ M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/reorganized by row subject and evidence boundary; current occurrence docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@19.cell[4] at docs/mysql/02-isolation/anomaly-catalog.md:19 C02310 base docs/mysql/02-isolation/anomaly-catalog.md:22 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@22.cell[5] catalog-cell ✅ M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/reorganized by row subject and evidence boundary; current occurrence docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@19.cell[5] at docs/mysql/02-isolation/anomaly-catalog.md:19 C00063 base docs/mysql/02-isolation/anomaly-catalog.md:23 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@23.cell[0] catalog-cell G1c M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Retained with scoped support; current occurrence docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@20.cell[0] at docs/mysql/02-isolation/anomaly-catalog.md:20 C00064 base docs/mysql/02-isolation/anomaly-catalog.md:23 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@23.cell[1] catalog-cell **Circular information flow** M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/reorganized by row subject and evidence boundary; current occurrence docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@20.cell[1] at docs/mysql/02-isolation/anomaly-catalog.md:20 C00065 base docs/mysql/02-isolation/anomaly-catalog.md:23 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@23.cell[2] catalog-cell ⚠️ [happens](#circular-information-flow-g1c) M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/reorganized by row subject and evidence boundary; current occurrence docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@20.cell[2] at docs/mysql/02-isolation/anomaly-catalog.md:20 C00066 base docs/mysql/02-isolation/anomaly-catalog.md:23 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@23.cell[3] catalog-cell ✅ impossible, [proof](#circular-information-flow-g1c) M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/reorganized by row subject and evidence boundary; current occurrence docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@20.cell[3] at docs/mysql/02-isolation/anomaly-catalog.md:20 C00067 base docs/mysql/02-isolation/anomaly-catalog.md:23 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@23.cell[4] catalog-cell ✅ M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/reorganized by row subject and evidence boundary; current occurrence docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@20.cell[4] at docs/mysql/02-isolation/anomaly-catalog.md:20 C02311 base docs/mysql/02-isolation/anomaly-catalog.md:23 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@23.cell[5] catalog-cell ✅ M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/reorganized by row subject and evidence boundary; current occurrence docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@20.cell[5] at docs/mysql/02-isolation/anomaly-catalog.md:20 C00068 base docs/mysql/02-isolation/anomaly-catalog.md:24 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@24.cell[0] catalog-cell OTV M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Retained with scoped support; current occurrence docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@21.cell[0] at docs/mysql/02-isolation/anomaly-catalog.md:21 C00069 base docs/mysql/02-isolation/anomaly-catalog.md:24 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@24.cell[1] catalog-cell **Observed transaction vanishes** M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/reorganized by row subject and evidence boundary; current occurrence docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@21.cell[1] at docs/mysql/02-isolation/anomaly-catalog.md:21 C00070 base docs/mysql/02-isolation/anomaly-catalog.md:24 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@24.cell[2] catalog-cell ⚠️ [happens](#observed-transaction-vanishes-otv) M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/reorganized by row subject and evidence boundary; current occurrence docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@21.cell[2] at docs/mysql/02-isolation/anomaly-catalog.md:21 C00071 base docs/mysql/02-isolation/anomaly-catalog.md:24 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@24.cell[3] catalog-cell ✅ impossible, [proof](#observed-transaction-vanishes-otv) M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/reorganized by row subject and evidence boundary; current occurrence docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@21.cell[3] at docs/mysql/02-isolation/anomaly-catalog.md:21 C00072 base docs/mysql/02-isolation/anomaly-catalog.md:24 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@24.cell[4] catalog-cell ✅ M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/reorganized by row subject and evidence boundary; current occurrence docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@21.cell[4] at docs/mysql/02-isolation/anomaly-catalog.md:21 C02312 base docs/mysql/02-isolation/anomaly-catalog.md:24 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@24.cell[5] catalog-cell ✅ M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/reorganized by row subject and evidence boundary; current occurrence docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@21.cell[5] at docs/mysql/02-isolation/anomaly-catalog.md:21 C00073 base docs/mysql/02-isolation/anomaly-catalog.md:25 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@25.cell[0] catalog-cell P2 M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Retained with scoped support; current occurrence docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@22.cell[0] at docs/mysql/02-isolation/anomaly-catalog.md:22 C00074 base docs/mysql/02-isolation/anomaly-catalog.md:25 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@25.cell[1] catalog-cell **Non-repeatable read** M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/reorganized by row subject and evidence boundary; current occurrence docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@22.cell[1] at docs/mysql/02-isolation/anomaly-catalog.md:22 C00075 base docs/mysql/02-isolation/anomaly-catalog.md:25 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@25.cell[2] catalog-cell ⚠️ M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/reorganized by row subject and evidence boundary; current occurrence docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@22.cell[2] at docs/mysql/02-isolation/anomaly-catalog.md:22 C00076 base docs/mysql/02-isolation/anomaly-catalog.md:25 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@25.cell[3] catalog-cell ⚠️ [happens](/mysql/02-isolation/read-committed#non-repeatable-reads) M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/reorganized by row subject and evidence boundary; current occurrence docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@22.cell[3] at docs/mysql/02-isolation/anomaly-catalog.md:22 C00077 base docs/mysql/02-isolation/anomaly-catalog.md:25 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@25.cell[4] catalog-cell ✅ prevented (plain SELECTs), [proof](/mysql/02-isolation/repeatable-read#one-snapshot-no-phantoms) M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/reorganized by row subject and evidence boundary; current occurrence docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@22.cell[4] at docs/mysql/02-isolation/anomaly-catalog.md:22 C02313 base docs/mysql/02-isolation/anomaly-catalog.md:25 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@25.cell[5] catalog-cell ✅ M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/reorganized by row subject and evidence boundary; current occurrence docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@22.cell[5] at docs/mysql/02-isolation/anomaly-catalog.md:22 C00078 base docs/mysql/02-isolation/anomaly-catalog.md:26 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@26.cell[0] catalog-cell G-single M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Retained with scoped support; current occurrence docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@23.cell[0] at docs/mysql/02-isolation/anomaly-catalog.md:23 C00079 base docs/mysql/02-isolation/anomaly-catalog.md:26 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@26.cell[1] catalog-cell **Read skew** M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/reorganized by row subject and evidence boundary; current occurrence docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@23.cell[1] at docs/mysql/02-isolation/anomaly-catalog.md:23 C00080 base docs/mysql/02-isolation/anomaly-catalog.md:26 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@26.cell[2] catalog-cell ⚠️ M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/reorganized by row subject and evidence boundary; current occurrence docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@23.cell[2] at docs/mysql/02-isolation/anomaly-catalog.md:23 C00081 base docs/mysql/02-isolation/anomaly-catalog.md:26 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@26.cell[3] catalog-cell ⚠️ [happens](/mysql/02-isolation/read-committed#read-skew-a-total-that-never-existed) M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/reorganized by row subject and evidence boundary; current occurrence docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@23.cell[3] at docs/mysql/02-isolation/anomaly-catalog.md:23 C00082 base docs/mysql/02-isolation/anomaly-catalog.md:26 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@26.cell[4] catalog-cell ⚠️ plain SELECTs safe, [but writes aren't](/mysql/02-isolation/repeatable-read#your-delete-and-your-select-live-in-different-worlds) M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/reorganized by row subject and evidence boundary; current occurrence docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@23.cell[4] at docs/mysql/02-isolation/anomaly-catalog.md:23 C02314 base docs/mysql/02-isolation/anomaly-catalog.md:26 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@26.cell[5] catalog-cell ✅ M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/reorganized by row subject and evidence boundary; current occurrence docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@23.cell[5] at docs/mysql/02-isolation/anomaly-catalog.md:23 C00083 base docs/mysql/02-isolation/anomaly-catalog.md:27 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@27.cell[0] catalog-cell PMP M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Retained with scoped support; current occurrence docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@24.cell[0] at docs/mysql/02-isolation/anomaly-catalog.md:24 C00084 base docs/mysql/02-isolation/anomaly-catalog.md:27 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@27.cell[1] catalog-cell **Phantom read** M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/reorganized by row subject and evidence boundary; current occurrence docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@24.cell[1] at docs/mysql/02-isolation/anomaly-catalog.md:24 C00085 base docs/mysql/02-isolation/anomaly-catalog.md:27 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@27.cell[2] catalog-cell ⚠️ M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/reorganized by row subject and evidence boundary; current occurrence docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@24.cell[2] at docs/mysql/02-isolation/anomaly-catalog.md:24 C00086 base docs/mysql/02-isolation/anomaly-catalog.md:27 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@27.cell[3] catalog-cell ⚠️ [happens](/mysql/02-isolation/read-committed#phantoms) M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/reorganized by row subject and evidence boundary; current occurrence docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@24.cell[3] at docs/mysql/02-isolation/anomaly-catalog.md:24 C00087 base docs/mysql/02-isolation/anomaly-catalog.md:27 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@27.cell[4] catalog-cell ⚠️ plain SELECTs safe, [current reads see phantoms](/mysql/02-isolation/repeatable-read#current-reads-punch-holes-in-the-snapshot) M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/reorganized by row subject and evidence boundary; current occurrence docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@24.cell[4] at docs/mysql/02-isolation/anomaly-catalog.md:24 C02315 base docs/mysql/02-isolation/anomaly-catalog.md:27 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@27.cell[5] catalog-cell ✅ M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/reorganized by row subject and evidence boundary; current occurrence docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@24.cell[5] at docs/mysql/02-isolation/anomaly-catalog.md:24 C00088 base docs/mysql/02-isolation/anomaly-catalog.md:28 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@28.cell[0] catalog-cell P4 M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Retained with scoped support; current occurrence docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@25.cell[0] at docs/mysql/02-isolation/anomaly-catalog.md:25 C00089 base docs/mysql/02-isolation/anomaly-catalog.md:28 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@28.cell[1] catalog-cell **Lost update** M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/reorganized by row subject and evidence boundary; current occurrence docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@25.cell[1] at docs/mysql/02-isolation/anomaly-catalog.md:25 C00090 base docs/mysql/02-isolation/anomaly-catalog.md:28 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@28.cell[2] catalog-cell ⚠️ M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/reorganized by row subject and evidence boundary; current occurrence docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@25.cell[2] at docs/mysql/02-isolation/anomaly-catalog.md:25 C00091 base docs/mysql/02-isolation/anomaly-catalog.md:28 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@28.cell[3] catalog-cell ⚠️ [happens](/mysql/02-isolation/lost-update#at-read-committed) M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/reorganized by row subject and evidence boundary; current occurrence docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@25.cell[3] at docs/mysql/02-isolation/anomaly-catalog.md:25 C00092 base docs/mysql/02-isolation/anomaly-catalog.md:28 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@28.cell[4] catalog-cell ⚠️ **still happens**, [proof](/mysql/02-isolation/lost-update#repeatable-read-does-not-save-you) M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/reorganized by row subject and evidence boundary; current occurrence docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@25.cell[4] at docs/mysql/02-isolation/anomaly-catalog.md:25 C02316 base docs/mysql/02-isolation/anomaly-catalog.md:28 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@28.cell[5] catalog-cell ✅ prevented (locks + deadlock) M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/reorganized by row subject and evidence boundary; current occurrence docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@25.cell[5] at docs/mysql/02-isolation/anomaly-catalog.md:25 C00093 base docs/mysql/02-isolation/anomaly-catalog.md:29 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@29.cell[0] catalog-cell G2-item / G2 M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/reorganized by row subject and evidence boundary; current occurrence docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@26.cell[0] at docs/mysql/02-isolation/anomaly-catalog.md:26; current occurrence docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@27.cell[0] at docs/mysql/02-isolation/anomaly-catalog.md:27 C00094 base docs/mysql/02-isolation/anomaly-catalog.md:29 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@29.cell[1] catalog-cell **Write skew** (item & predicate) M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/reorganized by row subject and evidence boundary; current occurrence docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@26.cell[1] at docs/mysql/02-isolation/anomaly-catalog.md:26; current occurrence docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@27.cell[1] at docs/mysql/02-isolation/anomaly-catalog.md:27 C00095 base docs/mysql/02-isolation/anomaly-catalog.md:29 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@29.cell[2] catalog-cell ⚠️ M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/reorganized by row subject and evidence boundary; current occurrence docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@26.cell[2] at docs/mysql/02-isolation/anomaly-catalog.md:26; current occurrence docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@27.cell[2] at docs/mysql/02-isolation/anomaly-catalog.md:27 C00096 base docs/mysql/02-isolation/anomaly-catalog.md:29 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@29.cell[3] catalog-cell ⚠️ M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/reorganized by row subject and evidence boundary; current occurrence docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@26.cell[3] at docs/mysql/02-isolation/anomaly-catalog.md:26; current occurrence docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@27.cell[3] at docs/mysql/02-isolation/anomaly-catalog.md:27 C00097 base docs/mysql/02-isolation/anomaly-catalog.md:29 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@29.cell[4] catalog-cell ⚠️ [happens](/mysql/02-isolation/serializable#write-skew-at-repeatable-read) M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/reorganized by row subject and evidence boundary; current occurrence docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@26.cell[4] at docs/mysql/02-isolation/anomaly-catalog.md:26; current occurrence docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@27.cell[4] at docs/mysql/02-isolation/anomaly-catalog.md:27 C02317 base docs/mysql/02-isolation/anomaly-catalog.md:29 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@29.cell[5] catalog-cell ✅ prevented, [proof](/mysql/02-isolation/serializable#serializable-stops-it-with-locks) M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/reorganized by row subject and evidence boundary; current occurrence docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@26.cell[5] at docs/mysql/02-isolation/anomaly-catalog.md:26; current occurrence docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@27.cell[5] at docs/mysql/02-isolation/anomaly-catalog.md:27 C00098 base docs/mysql/02-isolation/anomaly-catalog.md:31 docs/mysql/02-isolation/anomaly-catalog.md### The MySQL-specific pattern/line@31 lesson-unit ## The MySQL-specific pattern M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Retained with scoped support; current occurrence docs/mysql/02-isolation/anomaly-catalog.md### The MySQL-specific pattern/line@67 at docs/mysql/02-isolation/anomaly-catalog.md:67 C00099 base docs/mysql/02-isolation/anomaly-catalog.md:33 docs/mysql/02-isolation/anomaly-catalog.md### The MySQL-specific pattern/paragraph@33 lesson-unit Reading this table column by column, one theme emerges: on MySQL, isolation levels protect reads, not read-modify-write cycles. REPEATABLE READ gives your SELECTs a perfectly stable world, and your UPDATEs a completely different, current one. Everything in the bottom half of the table is fixed with explicit locking or SQL-side arithmetic, not with the isolation knob. M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/removed; corrected current source in docs/mysql/02-isolation/anomaly-catalog.md, see semantic decisions A1-A10 C00100 base docs/mysql/02-isolation/anomaly-catalog.md:39 docs/mysql/02-isolation/anomaly-catalog.md### The MySQL-specific pattern/paragraph@39 lesson-unit PostgreSQL's catalog looks different: its RR turns lost updates into retryable errors, its SERIALIZABLE detects write skew without locks, and its weakest level is Hermitage-clean. See [both engines' answers side by side](/concepts/anomalies-by-engine). The three ⚠️ cells in MySQL's REPEATABLE READ column are exactly where Hermitage's results for the two databases diverge, and all three trace back to [current reads](/mysql/02-isolation/repeatable-read). M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/removed; corrected current source in docs/mysql/02-isolation/anomaly-catalog.md, see semantic decisions A1-A10 C00101 base docs/mysql/02-isolation/anomaly-catalog.md:45 docs/mysql/02-isolation/anomaly-catalog.md### What READ UNCOMMITTED really costs/line@45 lesson-unit ## What READ UNCOMMITTED really costs M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Retained with scoped support; current occurrence docs/mysql/02-isolation/anomaly-catalog.md### What READ UNCOMMITTED really costs/line@76 at docs/mysql/02-isolation/anomaly-catalog.md:76 C00102 base docs/mysql/02-isolation/anomaly-catalog.md:47 docs/mysql/02-isolation/anomaly-catalog.md### What READ UNCOMMITTED really costs/paragraph@47 lesson-unit The G1 family and OTV are all ✅ from READ COMMITTED up, but unlike PostgreSQL, MySQL really does serve dirty data if you ask for it, so each one is observable: M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/removed; corrected current source in docs/mysql/02-isolation/anomaly-catalog.md, see semantic decisions A1-A10 C00103 base docs/mysql/02-isolation/anomaly-catalog.md:50 docs/mysql/02-isolation/anomaly-catalog.md#### Dirty writes (G0)/line@50 lesson-unit ### Dirty writes (G0) M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Retained with scoped support; current occurrence docs/mysql/02-isolation/anomaly-catalog.md#### Dirty writes (G0)/line@81 at docs/mysql/02-isolation/anomaly-catalog.md:81 C00104 base docs/mysql/02-isolation/anomaly-catalog.md:52 docs/mysql/02-isolation/anomaly-catalog.md#### Dirty writes (G0)/paragraph@52 lesson-unit The one guarantee *every* level keeps: InnoDB always takes exclusive row locks for writes, so interleaved writes can't produce a state no serial order could: M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/removed; corrected current source in docs/mysql/02-isolation/anomaly-catalog.md, see semantic decisions A1-A10 C00105 base docs/mysql/02-isolation/anomaly-catalog.md:55 docs/mysql/02-isolation/anomaly-catalog.md#### Dirty writes (G0)/line@55 lesson-unit M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Retained with scoped support; current occurrence docs/mysql/02-isolation/anomaly-catalog.md#### Dirty writes (G0)/line@87 at docs/mysql/02-isolation/anomaly-catalog.md:87 C00106 base docs/mysql/02-isolation/anomaly-catalog.md:57 docs/mysql/02-isolation/anomaly-catalog.md#### Intermediate reads (G1b)/line@57 lesson-unit ### Intermediate reads (G1b) M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Retained with scoped support; current occurrence docs/mysql/02-isolation/anomaly-catalog.md#### Intermediate reads (G1b)/line@89 at docs/mysql/02-isolation/anomaly-catalog.md:89 C00107 base docs/mysql/02-isolation/anomaly-catalog.md:59 docs/mysql/02-isolation/anomaly-catalog.md#### Intermediate reads (G1b)/paragraph@59 lesson-unit At READ UNCOMMITTED you don't only read uncommitted data: you read *drafts* the writer later overwrites, values that are never part of any committed history: M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/removed; corrected current source in docs/mysql/02-isolation/anomaly-catalog.md, see semantic decisions A1-A10 C00108 base docs/mysql/02-isolation/anomaly-catalog.md:62 docs/mysql/02-isolation/anomaly-catalog.md#### Intermediate reads (G1b)/line@62 lesson-unit M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Retained with scoped support; current occurrence docs/mysql/02-isolation/anomaly-catalog.md#### Intermediate reads (G1b)/line@95 at docs/mysql/02-isolation/anomaly-catalog.md:95 C00109 base docs/mysql/02-isolation/anomaly-catalog.md:64 docs/mysql/02-isolation/anomaly-catalog.md#### Circular information flow (G1c)/line@64 lesson-unit ### Circular information flow (G1c) M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Retained with scoped support; current occurrence docs/mysql/02-isolation/anomaly-catalog.md#### Circular information flow (G1c)/line@97 at docs/mysql/02-isolation/anomaly-catalog.md:97 C00110 base docs/mysql/02-isolation/anomaly-catalog.md:66 docs/mysql/02-isolation/anomaly-catalog.md#### Circular information flow (G1c)/paragraph@66 lesson-unit Two transactions reading each other's uncommitted writes, an exchange with no serial explanation, and gone at READ COMMITTED: M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/removed; corrected current source in docs/mysql/02-isolation/anomaly-catalog.md, see semantic decisions A1-A10 C00111 base docs/mysql/02-isolation/anomaly-catalog.md:69 docs/mysql/02-isolation/anomaly-catalog.md#### Circular information flow (G1c)/line@69 lesson-unit M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Retained with scoped support; current occurrence docs/mysql/02-isolation/anomaly-catalog.md#### Circular information flow (G1c)/line@105 at docs/mysql/02-isolation/anomaly-catalog.md:105 C00112 base docs/mysql/02-isolation/anomaly-catalog.md:71 docs/mysql/02-isolation/anomaly-catalog.md#### Observed transaction vanishes (OTV)/line@71 lesson-unit ### Observed transaction vanishes (OTV) M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Retained with scoped support; current occurrence docs/mysql/02-isolation/anomaly-catalog.md#### Observed transaction vanishes (OTV)/line@107 at docs/mysql/02-isolation/anomaly-catalog.md:107 C00113 base docs/mysql/02-isolation/anomaly-catalog.md:73 docs/mysql/02-isolation/anomaly-catalog.md#### Observed transaction vanishes (OTV)/paragraph@73 lesson-unit At READ UNCOMMITTED a committed transaction can be visible in pieces: one row already overwritten by an uncommitted successor, the other still showing through: M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/removed; corrected current source in docs/mysql/02-isolation/anomaly-catalog.md, see semantic decisions A1-A10 C00114 base docs/mysql/02-isolation/anomaly-catalog.md:76 docs/mysql/02-isolation/anomaly-catalog.md#### Observed transaction vanishes (OTV)/line@76 lesson-unit M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Retained with scoped support; current occurrence docs/mysql/02-isolation/anomaly-catalog.md#### Observed transaction vanishes (OTV)/line@115 at docs/mysql/02-isolation/anomaly-catalog.md:115 C00115 base docs/mysql/02-isolation/anomaly-catalog.md:78 docs/mysql/02-isolation/anomaly-catalog.md### Error codes to retry on/line@78 lesson-unit ## Error codes to retry on M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Retained with scoped support; current occurrence docs/mysql/02-isolation/anomaly-catalog.md### Error codes to retry on/line@117 at docs/mysql/02-isolation/anomaly-catalog.md:117 C00116 base docs/mysql/02-isolation/anomaly-catalog.md:80 docs/mysql/02-isolation/anomaly-catalog.md### Error codes to retry on/table.row@80.cell[0] catalog-cell errno M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Retained with scoped support; current occurrence docs/mysql/02-isolation/anomaly-catalog.md### Error codes to retry on/table.row@123.cell[0] at docs/mysql/02-isolation/anomaly-catalog.md:123 C00117 base docs/mysql/02-isolation/anomaly-catalog.md:80 docs/mysql/02-isolation/anomaly-catalog.md### Error codes to retry on/table.row@80.cell[1] catalog-cell SQLSTATE M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Retained with scoped support; current occurrence docs/mysql/02-isolation/anomaly-catalog.md### Error codes to retry on/table.row@123.cell[1] at docs/mysql/02-isolation/anomaly-catalog.md:123 C00118 base docs/mysql/02-isolation/anomaly-catalog.md:80 docs/mysql/02-isolation/anomaly-catalog.md### Error codes to retry on/table.row@80.cell[2] catalog-cell Meaning M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/reorganized by row subject and evidence boundary; current occurrence docs/mysql/02-isolation/anomaly-catalog.md### Error codes to retry on/table.row@123.cell[2] at docs/mysql/02-isolation/anomaly-catalog.md:123 C02318 base docs/mysql/02-isolation/anomaly-catalog.md:80 docs/mysql/02-isolation/anomaly-catalog.md### Error codes to retry on/table.row@80.cell[3] catalog-cell Where you saw it M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/reorganized by row subject and evidence boundary; current occurrence docs/mysql/02-isolation/anomaly-catalog.md### Error codes to retry on/table.row@123.cell[3] at docs/mysql/02-isolation/anomaly-catalog.md:123 C00119 base docs/mysql/02-isolation/anomaly-catalog.md:81 docs/mysql/02-isolation/anomaly-catalog.md### Error codes to retry on/table.row@81.cell[0] catalog-cell --- M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Retained with scoped support; current occurrence docs/mysql/02-isolation/anomaly-catalog.md### Error codes to retry on/table.row@124.cell[0] at docs/mysql/02-isolation/anomaly-catalog.md:124 C00120 base docs/mysql/02-isolation/anomaly-catalog.md:81 docs/mysql/02-isolation/anomaly-catalog.md### Error codes to retry on/table.row@81.cell[1] catalog-cell --- M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Retained with scoped support; current occurrence docs/mysql/02-isolation/anomaly-catalog.md### Error codes to retry on/table.row@124.cell[1] at docs/mysql/02-isolation/anomaly-catalog.md:124 C00121 base docs/mysql/02-isolation/anomaly-catalog.md:81 docs/mysql/02-isolation/anomaly-catalog.md### Error codes to retry on/table.row@81.cell[2] catalog-cell --- M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Retained with scoped support; current occurrence docs/mysql/02-isolation/anomaly-catalog.md### Error codes to retry on/table.row@124.cell[2] at docs/mysql/02-isolation/anomaly-catalog.md:124 C02319 base docs/mysql/02-isolation/anomaly-catalog.md:81 docs/mysql/02-isolation/anomaly-catalog.md### Error codes to retry on/table.row@81.cell[3] catalog-cell --- M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Retained with scoped support; current occurrence docs/mysql/02-isolation/anomaly-catalog.md### Error codes to retry on/table.row@124.cell[3] at docs/mysql/02-isolation/anomaly-catalog.md:124 C00122 base docs/mysql/02-isolation/anomaly-catalog.md:82 docs/mysql/02-isolation/anomaly-catalog.md### Error codes to retry on/table.row@82.cell[0] catalog-cell `1213` M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/reorganized by row subject and evidence boundary; current occurrence docs/mysql/02-isolation/anomaly-catalog.md### Error codes to retry on/table.row@125.cell[0] at docs/mysql/02-isolation/anomaly-catalog.md:125 C00123 base docs/mysql/02-isolation/anomaly-catalog.md:82 docs/mysql/02-isolation/anomaly-catalog.md### Error codes to retry on/table.row@82.cell[1] catalog-cell 40001 M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Retained with scoped support; current occurrence docs/mysql/02-isolation/anomaly-catalog.md### Error codes to retry on/table.row@125.cell[1] at docs/mysql/02-isolation/anomaly-catalog.md:125 C00124 base docs/mysql/02-isolation/anomaly-catalog.md:82 docs/mysql/02-isolation/anomaly-catalog.md### Error codes to retry on/table.row@82.cell[2] catalog-cell Deadlock found; transaction rolled back M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/reorganized by row subject and evidence boundary; current occurrence docs/mysql/02-isolation/anomaly-catalog.md### Error codes to retry on/table.row@125.cell[2] at docs/mysql/02-isolation/anomaly-catalog.md:125 C02320 base docs/mysql/02-isolation/anomaly-catalog.md:82 docs/mysql/02-isolation/anomaly-catalog.md### Error codes to retry on/table.row@82.cell[3] catalog-cell [SERIALIZABLE write skew](/mysql/02-isolation/serializable), [deadlocks](/mysql/03-locking/deadlocks) M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/reorganized by row subject and evidence boundary; current occurrence docs/mysql/02-isolation/anomaly-catalog.md### Error codes to retry on/table.row@125.cell[3] at docs/mysql/02-isolation/anomaly-catalog.md:125 C00125 base docs/mysql/02-isolation/anomaly-catalog.md:83 docs/mysql/02-isolation/anomaly-catalog.md### Error codes to retry on/table.row@83.cell[0] catalog-cell `1205` M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/reorganized by row subject and evidence boundary; current occurrence docs/mysql/02-isolation/anomaly-catalog.md### Error codes to retry on/table.row@126.cell[0] at docs/mysql/02-isolation/anomaly-catalog.md:126 C00126 base docs/mysql/02-isolation/anomaly-catalog.md:83 docs/mysql/02-isolation/anomaly-catalog.md### Error codes to retry on/table.row@83.cell[1] catalog-cell HY000 M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Retained with scoped support; current occurrence docs/mysql/02-isolation/anomaly-catalog.md### Error codes to retry on/table.row@126.cell[1] at docs/mysql/02-isolation/anomaly-catalog.md:126 C00127 base docs/mysql/02-isolation/anomaly-catalog.md:83 docs/mysql/02-isolation/anomaly-catalog.md### Error codes to retry on/table.row@83.cell[2] catalog-cell Lock wait timeout; **statement** rolled back, transaction survives M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/reorganized by row subject and evidence boundary; current occurrence docs/mysql/02-isolation/anomaly-catalog.md### Error codes to retry on/table.row@126.cell[2] at docs/mysql/02-isolation/anomaly-catalog.md:126 C02321 base docs/mysql/02-isolation/anomaly-catalog.md:83 docs/mysql/02-isolation/anomaly-catalog.md### Error codes to retry on/table.row@83.cell[3] catalog-cell [lock timeouts](/mysql/03-locking/nowait-skip-locked) M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/reorganized by row subject and evidence boundary; current occurrence docs/mysql/02-isolation/anomaly-catalog.md### Error codes to retry on/table.row@126.cell[3] at docs/mysql/02-isolation/anomaly-catalog.md:126 C00128 base docs/mysql/02-isolation/anomaly-catalog.md:85 docs/mysql/02-isolation/anomaly-catalog.md### Further reading/line@85 lesson-unit ## Further reading M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Retained with scoped support; current occurrence docs/mysql/02-isolation/anomaly-catalog.md### Further reading/line@133 at docs/mysql/02-isolation/anomaly-catalog.md:133 C00129 base docs/mysql/02-isolation/anomaly-catalog.md:87 docs/mysql/02-isolation/anomaly-catalog.md### Further reading/paragraph@87 lesson-unit - [Hermitage](https://github.com/ept/hermitage): runnable isolation tests for MySQL, PostgreSQL, Oracle, and more; this chapter proves every MySQL case it covers - [MySQL docs: Transaction Isolation Levels](https://dev.mysql.com/doc/refman/8.4/en/innodb-transaction-isolation-levels.html) - [Anomalies by engine](/concepts/anomalies-by-engine): both engines' answers collapsed to one cell each, in adjacent columns - [The same catalog for PostgreSQL](/postgres/02-isolation/anomaly-catalog): the full grid M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/removed; corrected current source in docs/mysql/02-isolation/anomaly-catalog.md, see semantic decisions A1-A10 C00130 base docs/mysql/02-isolation/lost-update.md:1 docs/mysql/02-isolation/lost-update.md## Lost updates/line@1 lesson-unit # Lost updates M5 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Retained with scoped support; current occurrence docs/mysql/02-isolation/lost-update.md## Lost updates/line@1 at docs/mysql/02-isolation/lost-update.md:1 C00131 base docs/mysql/02-isolation/lost-update.md:3 docs/mysql/02-isolation/lost-update.md## Lost updates/paragraph@3 lesson-unit Two clients read a value, compute a new one in application code, and write it back. One update silently erases the other. Why the read-modify-write pattern loses data is [Concepts: the lost update problem](/concepts/lost-update); this page is about what makes MySQL's version of it uniquely dangerous. M5 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/removed; corrected current source in docs/mysql/02-isolation/lost-update.md, see semantic decisions A1-A10 C00132 base docs/mysql/02-isolation/lost-update.md:8 docs/mysql/02-isolation/lost-update.md### At READ COMMITTED/line@8 lesson-unit ## At READ COMMITTED M5 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Retained with scoped support; current occurrence docs/mysql/02-isolation/lost-update.md### At READ COMMITTED/line@8 at docs/mysql/02-isolation/lost-update.md:8 C00133 base docs/mysql/02-isolation/lost-update.md:10 docs/mysql/02-isolation/lost-update.md### At READ COMMITTED/line@10 lesson-unit M5 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Retained with scoped support; current occurrence docs/mysql/02-isolation/lost-update.md### At READ COMMITTED/line@10 at docs/mysql/02-isolation/lost-update.md:10 C00134 base docs/mysql/02-isolation/lost-update.md:12 docs/mysql/02-isolation/lost-update.md### REPEATABLE READ does *not* save you/line@12 lesson-unit ## REPEATABLE READ does *not* save you M5 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Retained with scoped support; current occurrence docs/mysql/02-isolation/lost-update.md### REPEATABLE READ does *not* save you/line@12 at docs/mysql/02-isolation/lost-update.md:12 C00135 base docs/mysql/02-isolation/lost-update.md:14 docs/mysql/02-isolation/lost-update.md### REPEATABLE READ does *not* save you/paragraph@14 lesson-unit This is the sharpest MySQL/PostgreSQL divergence in the whole chapter. PostgreSQL's REPEATABLE READ [detects the stale write and aborts it](/postgres/02-isolation/lost-update) with `40001`. MySQL's UPDATE is a [current read](/mysql/02-isolation/repeatable-read): it applies your stale arithmetic to the newest row version and raises nothing: M5 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/removed; corrected current source in docs/mysql/02-isolation/lost-update.md, see semantic decisions A1-A10 C00136 base docs/mysql/02-isolation/lost-update.md:19 docs/mysql/02-isolation/lost-update.md### REPEATABLE READ does *not* save you/line@19 lesson-unit ::: warning The isolation knob will not fix this M5 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/removed; corrected current source in docs/mysql/02-isolation/lost-update.md, see semantic decisions A1-A10 C00137 base docs/mysql/02-isolation/lost-update.md:20 docs/mysql/02-isolation/lost-update.md### REPEATABLE READ does *not* save you/paragraph@20 lesson-unit Every ORM `save()` that reads, computes, and writes back has this bug at MySQL's default level. The fix is structural (atomic SQL, a locking read, or a version column), not a `SET TRANSACTION` away. M5 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/removed; corrected current source in docs/mysql/02-isolation/lost-update.md, see semantic decisions A1-A10 C00138 base docs/mysql/02-isolation/lost-update.md:23 docs/mysql/02-isolation/lost-update.md### REPEATABLE READ does *not* save you/line@23 lesson-unit ::: M5 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Retained with scoped support; current occurrence docs/mysql/02-isolation/lost-update.md### REPEATABLE READ does *not* save you/line@24 at docs/mysql/02-isolation/lost-update.md:24 C00139 base docs/mysql/02-isolation/lost-update.md:25 docs/mysql/02-isolation/lost-update.md### REPEATABLE READ does *not* save you/line@25 lesson-unit M5 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Retained with scoped support; current occurrence docs/mysql/02-isolation/lost-update.md### REPEATABLE READ does *not* save you/line@26 at docs/mysql/02-isolation/lost-update.md:26 C00140 base docs/mysql/02-isolation/lost-update.md:27 docs/mysql/02-isolation/lost-update.md### The fixes/line@27 lesson-unit ## The fixes M5 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Retained with scoped support; current occurrence docs/mysql/02-isolation/lost-update.md### The fixes/line@28 at docs/mysql/02-isolation/lost-update.md:28 C00141 base docs/mysql/02-isolation/lost-update.md:29 docs/mysql/02-isolation/lost-update.md### The fixes/paragraph@29 lesson-unit Raising the isolation level is not one of them (short of SERIALIZABLE). On MySQL you fix lost updates *structurally*: atomic UPDATEs, `SELECT … FOR UPDATE` ([chapter 3](/mysql/03-locking/row-locks)), or an optimistic version column checked via `affectedRows`. The three patterns are defined in [the concept page](/concepts/lost-update#the-fixes) and each proven with a transcript in [fixing lost updates](/mysql/05-patterns/fixing-lost-updates). M5 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/removed; corrected current source in docs/mysql/02-isolation/lost-update.md, see semantic decisions A1-A10 C00142 base docs/mysql/02-isolation/lost-update.md:36 docs/mysql/02-isolation/lost-update.md### The fixes/paragraph@36 lesson-unit A lost update is silent: the transcript above ends with `110` where two +10 deposits on `100` should have produced `120`, and nothing errored. Nothing short of SERIALIZABLE stops it on MySQL: if your app reads a value, computes from it, and writes it back, the bug is there until you apply one of the three fixes. If you're porting from PostgreSQL, code that leaned on its REPEATABLE READ conflict detection loses that protection the moment it runs here. M5 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/removed; corrected current source in docs/mysql/02-isolation/lost-update.md, see semantic decisions A1-A10 C00143 base docs/mysql/02-isolation/lost-update.md:42 docs/mysql/02-isolation/lost-update.md### Further reading/line@42 lesson-unit ## Further reading M5 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Retained with scoped support; current occurrence docs/mysql/02-isolation/lost-update.md### Further reading/line@44 at docs/mysql/02-isolation/lost-update.md:44 C00144 base docs/mysql/02-isolation/lost-update.md:44 docs/mysql/02-isolation/lost-update.md### Further reading/paragraph@44 lesson-unit - [MySQL docs: Locking Reads](https://dev.mysql.com/doc/refman/8.4/en/innodb-locking-reads.html) - [The same lesson on PostgreSQL](/postgres/02-isolation/lost-update) M5 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/removed; corrected current source in docs/mysql/02-isolation/lost-update.md, see semantic decisions A1-A10 C00145 base docs/mysql/02-isolation/read-committed.md:1 docs/mysql/02-isolation/read-committed.md## Read Committed/line@1 lesson-unit # Read Committed M6 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Retained with scoped support; current occurrence docs/mysql/02-isolation/read-committed.md## Read Committed/line@1 at docs/mysql/02-isolation/read-committed.md:1 C00146 base docs/mysql/02-isolation/read-committed.md:3 docs/mysql/02-isolation/read-committed.md## Read Committed/paragraph@3 lesson-unit At READ COMMITTED, every statement gets a fresh snapshot: it sees everything committed by the time *it* starts. Within one transaction, two identical reads can disagree, because the world moved between them. M6 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/removed; corrected current source in docs/mysql/02-isolation/read-committed.md, see semantic decisions A1-A10 C00147 base docs/mysql/02-isolation/read-committed.md:7 docs/mysql/02-isolation/read-committed.md### Non-repeatable reads/line@7 lesson-unit ## Non-repeatable reads M6 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Retained with scoped support; current occurrence docs/mysql/02-isolation/read-committed.md### Non-repeatable reads/line@9 at docs/mysql/02-isolation/read-committed.md:9 C00148 base docs/mysql/02-isolation/read-committed.md:9 docs/mysql/02-isolation/read-committed.md### Non-repeatable reads/line@9 lesson-unit M6 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Retained with scoped support; current occurrence docs/mysql/02-isolation/read-committed.md### Non-repeatable reads/line@15 at docs/mysql/02-isolation/read-committed.md:15 C00149 base docs/mysql/02-isolation/read-committed.md:11 docs/mysql/02-isolation/read-committed.md### Phantoms/line@11 lesson-unit ## Phantoms M6 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Retained with scoped support; current occurrence docs/mysql/02-isolation/read-committed.md### Phantoms/line@17 at docs/mysql/02-isolation/read-committed.md:17 C00150 base docs/mysql/02-isolation/read-committed.md:13 docs/mysql/02-isolation/read-committed.md### Phantoms/paragraph@13 lesson-unit The same effect on a *set* of rows: a `WHERE` clause can match rows in the second reading that didn't exist in the first. M6 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/removed; corrected current source in docs/mysql/02-isolation/read-committed.md, see semantic decisions A1-A10 C00151 base docs/mysql/02-isolation/read-committed.md:16 docs/mysql/02-isolation/read-committed.md### Phantoms/line@16 lesson-unit M6 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Retained with scoped support; current occurrence docs/mysql/02-isolation/read-committed.md### Phantoms/line@22 at docs/mysql/02-isolation/read-committed.md:22 C00152 base docs/mysql/02-isolation/read-committed.md:18 docs/mysql/02-isolation/read-committed.md### Read skew: a total that never existed/line@18 lesson-unit ## Read skew: a total that never existed M6 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Retained with scoped support; current occurrence docs/mysql/02-isolation/read-committed.md### Read skew: a total that never existed/line@24 at docs/mysql/02-isolation/read-committed.md:24 C00153 base docs/mysql/02-isolation/read-committed.md:20 docs/mysql/02-isolation/read-committed.md### Read skew: a total that never existed/paragraph@20 lesson-unit Non-repeatable reads have a nastier multi-row cousin, [read skew](/concepts/non-repeatable-read#read-skew): every row you read was committed and correct, yet the combination existed at no point in time: M6 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/removed; corrected current source in docs/mysql/02-isolation/read-committed.md, see semantic decisions A1-A10 C00154 base docs/mysql/02-isolation/read-committed.md:24 docs/mysql/02-isolation/read-committed.md### Read skew: a total that never existed/line@24 lesson-unit M6 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Retained with scoped support; current occurrence docs/mysql/02-isolation/read-committed.md### Read skew: a total that never existed/line@30 at docs/mysql/02-isolation/read-committed.md:30 C00155 base docs/mysql/02-isolation/read-committed.md:26 docs/mysql/02-isolation/read-committed.md### After the wait, the re-check/line@26 lesson-unit ## After the wait, the re-check M6 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Retained with scoped support; current occurrence docs/mysql/02-isolation/read-committed.md### After the wait, the re-check/line@32 at docs/mysql/02-isolation/read-committed.md:32 C00156 base docs/mysql/02-isolation/read-committed.md:28 docs/mysql/02-isolation/read-committed.md### After the wait, the re-check/paragraph@28 lesson-unit When an UPDATE waits for a row lock and finally gets it, the row may no longer match its `WHERE` clause. READ COMMITTED re-evaluates and silently skips it ([semi-consistent read](https://dev.mysql.com/doc/refman/8.4/en/innodb-transaction-isolation-levels.html#isolevel_read-committed)): M6 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/removed; corrected current source in docs/mysql/02-isolation/read-committed.md, see semantic decisions A1-A10 C00157 base docs/mysql/02-isolation/read-committed.md:32 docs/mysql/02-isolation/read-committed.md### After the wait, the re-check/line@32 lesson-unit M6 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Retained with scoped support; current occurrence docs/mysql/02-isolation/read-committed.md### After the wait, the re-check/line@39 at docs/mysql/02-isolation/read-committed.md:39 C00158 base docs/mysql/02-isolation/read-committed.md:34 docs/mysql/02-isolation/read-committed.md### After the wait, the re-check/paragraph@34 lesson-unit A fresh snapshot per statement means no dirty reads, but non-repeatable reads and phantoms are routine. If a report has to be internally consistent, run it at [REPEATABLE READ](/mysql/02-isolation/repeatable-read). And `Query OK, 0 rows affected` after a lock wait may mean the row escaped your `WHERE`, so code that assumes it updated exactly the rows it saw is wrong at this level. InnoDB also takes fewer gap locks here than at RR, which is one reason some heavy-write shops prefer it; locking is [chapter 3](/mysql/03-locking/row-locks). M6 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/removed; corrected current source in docs/mysql/02-isolation/read-committed.md, see semantic decisions A1-A10 C00159 base docs/mysql/02-isolation/read-committed.md:41 docs/mysql/02-isolation/read-committed.md### Further reading/line@41 lesson-unit ## Further reading M6 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Retained with scoped support; current occurrence docs/mysql/02-isolation/read-committed.md### Further reading/line@48 at docs/mysql/02-isolation/read-committed.md:48 C00160 base docs/mysql/02-isolation/read-committed.md:43 docs/mysql/02-isolation/read-committed.md### Further reading/paragraph@43 lesson-unit - [MySQL docs: READ COMMITTED](https://dev.mysql.com/doc/refman/8.4/en/innodb-transaction-isolation-levels.html#isolevel_read-committed) - [The same lesson on PostgreSQL](/postgres/02-isolation/read-committed) M6 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/removed; corrected current source in docs/mysql/02-isolation/read-committed.md, see semantic decisions A1-A10 C00161 base docs/mysql/02-isolation/repeatable-read.md:1 docs/mysql/02-isolation/repeatable-read.md## Repeatable Read/line@1 lesson-unit # Repeatable Read M7 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Retained with scoped support; current occurrence docs/mysql/02-isolation/repeatable-read.md## Repeatable Read/line@1 at docs/mysql/02-isolation/repeatable-read.md:1 C00162 base docs/mysql/02-isolation/repeatable-read.md:3 docs/mysql/02-isolation/repeatable-read.md## Repeatable Read/paragraph@3 lesson-unit At REPEATABLE READ (MySQL's default), the first read of the transaction takes one snapshot, and every later *plain SELECT* reads from that same frozen view: no non-repeatable reads, no phantoms. M7 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/removed; corrected current source in docs/mysql/02-isolation/repeatable-read.md, see semantic decisions A1-A10 C00163 base docs/mysql/02-isolation/repeatable-read.md:7 docs/mysql/02-isolation/repeatable-read.md## Repeatable Read/paragraph@7 lesson-unit But only plain SELECTs. UPDATE, DELETE, and `SELECT … FOR UPDATE/SHARE` are current reads: they operate on the latest committed data, snapshot be damned. That asterisk is where MySQL's RR differs most from PostgreSQL's, and where ported assumptions break. M7 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/removed; corrected current source in docs/mysql/02-isolation/repeatable-read.md, see semantic decisions A1-A10 C00164 base docs/mysql/02-isolation/repeatable-read.md:11 docs/mysql/02-isolation/repeatable-read.md### One snapshot, no phantoms/line@11 lesson-unit ## One snapshot, no phantoms M7 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Retained with scoped support; current occurrence docs/mysql/02-isolation/repeatable-read.md### One snapshot, no phantoms/line@15 at docs/mysql/02-isolation/repeatable-read.md:15 C00165 base docs/mysql/02-isolation/repeatable-read.md:13 docs/mysql/02-isolation/repeatable-read.md### One snapshot, no phantoms/line@13 lesson-unit M7 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Retained with scoped support; current occurrence docs/mysql/02-isolation/repeatable-read.md### One snapshot, no phantoms/line@21 at docs/mysql/02-isolation/repeatable-read.md:21 C00166 base docs/mysql/02-isolation/repeatable-read.md:15 docs/mysql/02-isolation/repeatable-read.md### Current reads punch holes in the snapshot/line@15 lesson-unit ## Current reads punch holes in the snapshot M7 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Retained with scoped support; current occurrence docs/mysql/02-isolation/repeatable-read.md### Current reads punch holes in the snapshot/line@23 at docs/mysql/02-isolation/repeatable-read.md:23 C00167 base docs/mysql/02-isolation/repeatable-read.md:17 docs/mysql/02-isolation/repeatable-read.md### Current reads punch holes in the snapshot/paragraph@17 lesson-unit Watch a single transaction read `100`, then compute `+50` *from a value it has never seen*, then suddenly see `200`: M7 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/removed; corrected current source in docs/mysql/02-isolation/repeatable-read.md, see semantic decisions A1-A10 C00168 base docs/mysql/02-isolation/repeatable-read.md:20 docs/mysql/02-isolation/repeatable-read.md### Current reads punch holes in the snapshot/line@20 lesson-unit M7 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Retained with scoped support; current occurrence docs/mysql/02-isolation/repeatable-read.md### Current reads punch holes in the snapshot/line@29 at docs/mysql/02-isolation/repeatable-read.md:29 C00169 base docs/mysql/02-isolation/repeatable-read.md:22 docs/mysql/02-isolation/repeatable-read.md### Current reads punch holes in the snapshot/line@22 lesson-unit ::: warning Porting from PostgreSQL? M7 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Retained with scoped support; current occurrence docs/mysql/02-isolation/repeatable-read.md### Current reads punch holes in the snapshot/line@31 at docs/mysql/02-isolation/repeatable-read.md:31 C00170 base docs/mysql/02-isolation/repeatable-read.md:23 docs/mysql/02-isolation/repeatable-read.md### Current reads punch holes in the snapshot/paragraph@23 lesson-unit PostgreSQL's REPEATABLE READ *refuses* to update a row that changed after your snapshot (SQLSTATE `40001`, [see the PostgreSQL lesson](/postgres/02-isolation/repeatable-read)). MySQL never raises that error: the write goes through against the current version. Retry loops written for PostgreSQL have nothing to catch here, and [lost updates](/mysql/02-isolation/lost-update) that PostgreSQL would have blocked go undetected. M7 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/removed; corrected current source in docs/mysql/02-isolation/repeatable-read.md, see semantic decisions A1-A10 C00171 base docs/mysql/02-isolation/repeatable-read.md:29 docs/mysql/02-isolation/repeatable-read.md### Current reads punch holes in the snapshot/line@29 lesson-unit ::: M7 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Retained with scoped support; current occurrence docs/mysql/02-isolation/repeatable-read.md### Current reads punch holes in the snapshot/line@37 at docs/mysql/02-isolation/repeatable-read.md:37 C00172 base docs/mysql/02-isolation/repeatable-read.md:31 docs/mysql/02-isolation/repeatable-read.md### Your DELETE and your SELECT live in different worlds/line@31 lesson-unit ## Your DELETE and your SELECT live in different worlds M7 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Retained with scoped support; current occurrence docs/mysql/02-isolation/repeatable-read.md### Your DELETE and your SELECT live in different worlds/line@39 at docs/mysql/02-isolation/repeatable-read.md:39 C00173 base docs/mysql/02-isolation/repeatable-read.md:33 docs/mysql/02-isolation/repeatable-read.md### Your DELETE and your SELECT live in different worlds/paragraph@33 lesson-unit "Current reads get truly disorienting when a *predicate* is involved. A transaction can ""delete every row matching X"", delete nothing (the current data no longer matches), and then keep *seeing* snapshot rows that match X (Hermitage calls this the write-predicate variant of G-single):" M7 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/removed; corrected current source in docs/mysql/02-isolation/repeatable-read.md, see semantic decisions A1-A10 C00174 base docs/mysql/02-isolation/repeatable-read.md:38 docs/mysql/02-isolation/repeatable-read.md### Your DELETE and your SELECT live in different worlds/line@38 lesson-unit M7 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Retained with scoped support; current occurrence docs/mysql/02-isolation/repeatable-read.md### Your DELETE and your SELECT live in different worlds/line@45 at docs/mysql/02-isolation/repeatable-read.md:45 C00175 base docs/mysql/02-isolation/repeatable-read.md:40 docs/mysql/02-isolation/repeatable-read.md### Your DELETE and your SELECT live in different worlds/paragraph@40 lesson-unit REPEATABLE READ gives you one snapshot per transaction, taken by the first read rather than by `BEGIN`, and plain SELECTs stay phantom-free, stronger than the SQL standard asks for. Writes and locking reads bypass that snapshot as current reads, and once you modify a row your own SELECTs see the new version, so the snapshot is a default, not a wall. No `40001`-style serialization errors fire at this level, which leaves the anomalies RR can't stop, [lost updates](/mysql/02-isolation/lost-update) and [write skew](/mysql/02-isolation/serializable), to be handled with [locking reads](/mysql/03-locking/row-locks) or constraints. M7 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/removed; corrected current source in docs/mysql/02-isolation/repeatable-read.md, see semantic decisions A1-A10 C00176 base docs/mysql/02-isolation/repeatable-read.md:49 docs/mysql/02-isolation/repeatable-read.md### Further reading/line@49 lesson-unit ## Further reading M7 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Retained with scoped support; current occurrence docs/mysql/02-isolation/repeatable-read.md### Further reading/line@54 at docs/mysql/02-isolation/repeatable-read.md:54 C00177 base docs/mysql/02-isolation/repeatable-read.md:51 docs/mysql/02-isolation/repeatable-read.md### Further reading/paragraph@51 lesson-unit - [MySQL docs: REPEATABLE READ](https://dev.mysql.com/doc/refman/8.4/en/innodb-transaction-isolation-levels.html#isolevel_repeatable-read) - [MySQL docs: Locking Reads](https://dev.mysql.com/doc/refman/8.4/en/innodb-locking-reads.html) - [The same lesson on PostgreSQL](/postgres/02-isolation/repeatable-read) M7 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/removed; corrected current source in docs/mysql/02-isolation/repeatable-read.md, see semantic decisions A1-A10 C00178 base docs/mysql/02-isolation/serializable.md:1 docs/mysql/02-isolation/serializable.md## Serializable/line@1 lesson-unit # Serializable M8 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Retained with scoped support; current occurrence docs/mysql/02-isolation/serializable.md## Serializable/line@1 at docs/mysql/02-isolation/serializable.md:1 C00179 base docs/mysql/02-isolation/serializable.md:3 docs/mysql/02-isolation/serializable.md## Serializable/paragraph@3 lesson-unit Some anomalies have no write-write conflict to detect. In **[write skew](/concepts/write-skew)**, two transactions each read an invariant, each write to a *different* row, and both commit, jointly breaking the rule both of them checked. M8 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/removed; corrected current source in docs/mysql/02-isolation/serializable.md, see semantic decisions A1-A10 C00180 base docs/mysql/02-isolation/serializable.md:7 docs/mysql/02-isolation/serializable.md### Write skew at REPEATABLE READ/line@7 lesson-unit ## Write skew at REPEATABLE READ M8 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Retained with scoped support; current occurrence docs/mysql/02-isolation/serializable.md### Write skew at REPEATABLE READ/line@8 at docs/mysql/02-isolation/serializable.md:8 C00181 base docs/mysql/02-isolation/serializable.md:9 docs/mysql/02-isolation/serializable.md### Write skew at REPEATABLE READ/line@9 lesson-unit M8 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Retained with scoped support; current occurrence docs/mysql/02-isolation/serializable.md### Write skew at REPEATABLE READ/line@13 at docs/mysql/02-isolation/serializable.md:13 C00182 base docs/mysql/02-isolation/serializable.md:11 docs/mysql/02-isolation/serializable.md### SERIALIZABLE stops it (with locks)/line@11 lesson-unit ## SERIALIZABLE stops it (with locks) M8 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Retained with scoped support; current occurrence docs/mysql/02-isolation/serializable.md### SERIALIZABLE stops it (with locks)/line@15 at docs/mysql/02-isolation/serializable.md:15 C00183 base docs/mysql/02-isolation/serializable.md:13 docs/mysql/02-isolation/serializable.md### SERIALIZABLE stops it (with locks)/paragraph@13 lesson-unit MySQL's SERIALIZABLE is REPEATABLE READ plus one rule: plain SELECTs act as `SELECT … FOR SHARE`, so every row you read gets a shared lock. Now the two night-off requests collide: each doctor's UPDATE needs an exclusive lock on a row the *other* is holding a shared lock on. That's a cycle. InnoDB's deadlock detector fires instantly: M8 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/removed; corrected current source in docs/mysql/02-isolation/serializable.md, see semantic decisions A1-A10 C00184 base docs/mysql/02-isolation/serializable.md:18 docs/mysql/02-isolation/serializable.md### SERIALIZABLE stops it (with locks)/line@18 lesson-unit M8 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Retained with scoped support; current occurrence docs/mysql/02-isolation/serializable.md### SERIALIZABLE stops it (with locks)/line@25 at docs/mysql/02-isolation/serializable.md:25 C00185 base docs/mysql/02-isolation/serializable.md:20 docs/mysql/02-isolation/serializable.md### SERIALIZABLE stops it (with locks)/line@20 lesson-unit ::: info Two databases, two philosophies M8 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/removed; corrected current source in docs/mysql/02-isolation/serializable.md, see semantic decisions A1-A10 C00186 base docs/mysql/02-isolation/serializable.md:21 docs/mysql/02-isolation/serializable.md### SERIALIZABLE stops it (with locks)/paragraph@21 lesson-unit PostgreSQL's SERIALIZABLE ([SSI](/postgres/02-isolation/serializable)) lets both transactions run without blocking and aborts one at COMMIT with `40001`. MySQL's is the classic lock-based approach: readers block writers, conflicts surface as deadlocks (errno `1213`) mid-transaction. Same guarantee, very different failure mode: your retry logic must catch `1213`, and it will fire *before* commit, not at it. M8 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/removed; corrected current source in docs/mysql/02-isolation/serializable.md, see semantic decisions A1-A10 C00187 base docs/mysql/02-isolation/serializable.md:26 docs/mysql/02-isolation/serializable.md### SERIALIZABLE stops it (with locks)/line@26 lesson-unit ::: M8 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Retained with scoped support; current occurrence docs/mysql/02-isolation/serializable.md### SERIALIZABLE stops it (with locks)/line@41 at docs/mysql/02-isolation/serializable.md:41 C00188 base docs/mysql/02-isolation/serializable.md:28 docs/mysql/02-isolation/serializable.md### SERIALIZABLE stops it (with locks)/line@28 lesson-unit ::: warning Every SELECT becomes a locking read M8 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/removed; corrected current source in docs/mysql/02-isolation/serializable.md, see semantic decisions A1-A10 C00189 base docs/mysql/02-isolation/serializable.md:29 docs/mysql/02-isolation/serializable.md### SERIALIZABLE stops it (with locks)/paragraph@29 lesson-unit Switching SERIALIZABLE on globally turns your entire read traffic into shared-lock traffic: lock waits and deadlock storms where SELECTs used to be free. Scope it to the transactions whose invariants need it. M8 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/removed; corrected current source in docs/mysql/02-isolation/serializable.md, see semantic decisions A1-A10 C00190 base docs/mysql/02-isolation/serializable.md:32 docs/mysql/02-isolation/serializable.md### SERIALIZABLE stops it (with locks)/line@32 lesson-unit ::: M8 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Retained with scoped support; current occurrence docs/mysql/02-isolation/serializable.md### SERIALIZABLE stops it (with locks)/line@49 at docs/mysql/02-isolation/serializable.md:49 C00191 base docs/mysql/02-isolation/serializable.md:34 docs/mysql/02-isolation/serializable.md### SERIALIZABLE stops it (with locks)/paragraph@34 lesson-unit REPEATABLE READ won't stop write skew: both transactions commit and the invariant dies silently. SERIALIZABLE fixes that by turning every read into a shared lock, buying correctness through blocking, so expect deadlocks under contention: they're the mechanism here, not an accident, and your retry logic has to catch `1213`. The cheaper targeted fix, here as everywhere, is to make the conflict explicit with `SELECT … FOR UPDATE` on the rows the decision depends on ([locking reads](/mysql/03-locking/row-locks)). M8 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/removed; corrected current source in docs/mysql/02-isolation/serializable.md, see semantic decisions A1-A10 C00192 base docs/mysql/02-isolation/serializable.md:41 docs/mysql/02-isolation/serializable.md### Further reading/line@41 lesson-unit ## Further reading M8 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Retained with scoped support; current occurrence docs/mysql/02-isolation/serializable.md### Further reading/line@61 at docs/mysql/02-isolation/serializable.md:61 C00193 base docs/mysql/02-isolation/serializable.md:43 docs/mysql/02-isolation/serializable.md### Further reading/paragraph@43 lesson-unit - [MySQL docs: SERIALIZABLE](https://dev.mysql.com/doc/refman/8.4/en/innodb-transaction-isolation-levels.html#isolevel_serializable) - [MySQL docs: Deadlock Detection](https://dev.mysql.com/doc/refman/8.4/en/innodb-deadlock-detection.html) - [The same lesson on PostgreSQL](/postgres/02-isolation/serializable) M8 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/removed; corrected current source in docs/mysql/02-isolation/serializable.md, see semantic decisions A1-A10 C00194 base docs/mysql/02-isolation/snapshots-and-the-four-levels.md:1 docs/mysql/02-isolation/snapshots-and-the-four-levels.md## Snapshots & the four levels/line@1 lesson-unit # Snapshots & the four levels M9 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Retained with scoped support; current occurrence docs/mysql/02-isolation/snapshots-and-the-four-levels.md## Snapshots & the four levels/line@1 at docs/mysql/02-isolation/snapshots-and-the-four-levels.md:1 C00195 base docs/mysql/02-isolation/snapshots-and-the-four-levels.md:3 docs/mysql/02-isolation/snapshots-and-the-four-levels.md## Snapshots & the four levels/paragraph@3 lesson-unit InnoDB is an MVCC engine: readers look at a consistent snapshot instead of locking rows, so plain SELECTs never block writers and writers never block plain SELECTs. Which snapshot a statement sees, and when reads take locks anyway, is decided by the isolation level. M9 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/removed; corrected current source in docs/mysql/02-isolation/snapshots-and-the-four-levels.md, see semantic decisions A1-A10 C00196 base docs/mysql/02-isolation/snapshots-and-the-four-levels.md:7 docs/mysql/02-isolation/snapshots-and-the-four-levels.md## Snapshots & the four levels/paragraph@7 lesson-unit MySQL implements all four SQL-standard levels ([the ladder and its vocabulary, in theory](/concepts/isolation-levels)), and unlike PostgreSQL, all four are *actually different*: M9 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/removed; corrected current source in docs/mysql/02-isolation/snapshots-and-the-four-levels.md, see semantic decisions A1-A10 C00197 base docs/mysql/02-isolation/snapshots-and-the-four-levels.md:11 docs/mysql/02-isolation/snapshots-and-the-four-levels.md## Snapshots & the four levels/table.row@11.cell[0] catalog-cell Level M9 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Retained with scoped support; current occurrence docs/mysql/02-isolation/snapshots-and-the-four-levels.md## Snapshots & the four levels/table.row@16.cell[0] at docs/mysql/02-isolation/snapshots-and-the-four-levels.md:16 C00198 base docs/mysql/02-isolation/snapshots-and-the-four-levels.md:11 docs/mysql/02-isolation/snapshots-and-the-four-levels.md## Snapshots & the four levels/table.row@11.cell[1] catalog-cell Dirty read M9 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/reorganized by row subject and evidence boundary; current occurrence docs/mysql/02-isolation/snapshots-and-the-four-levels.md## Snapshots & the four levels/table.row@16.cell[1] at docs/mysql/02-isolation/snapshots-and-the-four-levels.md:16; current occurrence docs/mysql/02-isolation/snapshots-and-the-four-levels.md## Snapshots & the four levels/table.row@16.cell[2] at docs/mysql/02-isolation/snapshots-and-the-four-levels.md:16 C00199 base docs/mysql/02-isolation/snapshots-and-the-four-levels.md:11 docs/mysql/02-isolation/snapshots-and-the-four-levels.md## Snapshots & the four levels/table.row@11.cell[2] catalog-cell Non-repeatable read M9 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/reorganized by row subject and evidence boundary; current occurrence docs/mysql/02-isolation/snapshots-and-the-four-levels.md## Snapshots & the four levels/table.row@16.cell[1] at docs/mysql/02-isolation/snapshots-and-the-four-levels.md:16; current occurrence docs/mysql/02-isolation/snapshots-and-the-four-levels.md## Snapshots & the four levels/table.row@16.cell[2] at docs/mysql/02-isolation/snapshots-and-the-four-levels.md:16 C00200 base docs/mysql/02-isolation/snapshots-and-the-four-levels.md:11 docs/mysql/02-isolation/snapshots-and-the-four-levels.md## Snapshots & the four levels/table.row@11.cell[3] catalog-cell Phantom M9 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/reorganized by row subject and evidence boundary; current occurrence docs/mysql/02-isolation/snapshots-and-the-four-levels.md## Snapshots & the four levels/table.row@16.cell[1] at docs/mysql/02-isolation/snapshots-and-the-four-levels.md:16; current occurrence docs/mysql/02-isolation/snapshots-and-the-four-levels.md## Snapshots & the four levels/table.row@16.cell[2] at docs/mysql/02-isolation/snapshots-and-the-four-levels.md:16 C02322 base docs/mysql/02-isolation/snapshots-and-the-four-levels.md:11 docs/mysql/02-isolation/snapshots-and-the-four-levels.md## Snapshots & the four levels/table.row@11.cell[4] catalog-cell Snapshot M9 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/reorganized by row subject and evidence boundary; current occurrence docs/mysql/02-isolation/snapshots-and-the-four-levels.md## Snapshots & the four levels/table.row@16.cell[1] at docs/mysql/02-isolation/snapshots-and-the-four-levels.md:16; current occurrence docs/mysql/02-isolation/snapshots-and-the-four-levels.md## Snapshots & the four levels/table.row@16.cell[2] at docs/mysql/02-isolation/snapshots-and-the-four-levels.md:16 C00201 base docs/mysql/02-isolation/snapshots-and-the-four-levels.md:12 docs/mysql/02-isolation/snapshots-and-the-four-levels.md## Snapshots & the four levels/table.row@12.cell[0] catalog-cell --- M9 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Retained with scoped support; current occurrence docs/mysql/02-isolation/snapshots-and-the-four-levels.md## Snapshots & the four levels/table.row@17.cell[0] at docs/mysql/02-isolation/snapshots-and-the-four-levels.md:17 C00202 base docs/mysql/02-isolation/snapshots-and-the-four-levels.md:12 docs/mysql/02-isolation/snapshots-and-the-four-levels.md## Snapshots & the four levels/table.row@12.cell[1] catalog-cell --- M9 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/reorganized by row subject and evidence boundary; current occurrence docs/mysql/02-isolation/snapshots-and-the-four-levels.md## Snapshots & the four levels/table.row@17.cell[1] at docs/mysql/02-isolation/snapshots-and-the-four-levels.md:17; current occurrence docs/mysql/02-isolation/snapshots-and-the-four-levels.md## Snapshots & the four levels/table.row@17.cell[2] at docs/mysql/02-isolation/snapshots-and-the-four-levels.md:17 C00203 base docs/mysql/02-isolation/snapshots-and-the-four-levels.md:12 docs/mysql/02-isolation/snapshots-and-the-four-levels.md## Snapshots & the four levels/table.row@12.cell[2] catalog-cell --- M9 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/reorganized by row subject and evidence boundary; current occurrence docs/mysql/02-isolation/snapshots-and-the-four-levels.md## Snapshots & the four levels/table.row@17.cell[1] at docs/mysql/02-isolation/snapshots-and-the-four-levels.md:17; current occurrence docs/mysql/02-isolation/snapshots-and-the-four-levels.md## Snapshots & the four levels/table.row@17.cell[2] at docs/mysql/02-isolation/snapshots-and-the-four-levels.md:17 C00204 base docs/mysql/02-isolation/snapshots-and-the-four-levels.md:12 docs/mysql/02-isolation/snapshots-and-the-four-levels.md## Snapshots & the four levels/table.row@12.cell[3] catalog-cell --- M9 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/reorganized by row subject and evidence boundary; current occurrence docs/mysql/02-isolation/snapshots-and-the-four-levels.md## Snapshots & the four levels/table.row@17.cell[1] at docs/mysql/02-isolation/snapshots-and-the-four-levels.md:17; current occurrence docs/mysql/02-isolation/snapshots-and-the-four-levels.md## Snapshots & the four levels/table.row@17.cell[2] at docs/mysql/02-isolation/snapshots-and-the-four-levels.md:17 C02323 base docs/mysql/02-isolation/snapshots-and-the-four-levels.md:12 docs/mysql/02-isolation/snapshots-and-the-four-levels.md## Snapshots & the four levels/table.row@12.cell[4] catalog-cell --- M9 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/reorganized by row subject and evidence boundary; current occurrence docs/mysql/02-isolation/snapshots-and-the-four-levels.md## Snapshots & the four levels/table.row@17.cell[1] at docs/mysql/02-isolation/snapshots-and-the-four-levels.md:17; current occurrence docs/mysql/02-isolation/snapshots-and-the-four-levels.md## Snapshots & the four levels/table.row@17.cell[2] at docs/mysql/02-isolation/snapshots-and-the-four-levels.md:17 C00205 base docs/mysql/02-isolation/snapshots-and-the-four-levels.md:13 docs/mysql/02-isolation/snapshots-and-the-four-levels.md## Snapshots & the four levels/table.row@13.cell[0] catalog-cell READ UNCOMMITTED M9 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Retained with scoped support; current occurrence docs/mysql/02-isolation/snapshots-and-the-four-levels.md## Snapshots & the four levels/table.row@18.cell[0] at docs/mysql/02-isolation/snapshots-and-the-four-levels.md:18 C00206 base docs/mysql/02-isolation/snapshots-and-the-four-levels.md:13 docs/mysql/02-isolation/snapshots-and-the-four-levels.md## Snapshots & the four levels/table.row@13.cell[1] catalog-cell **yes, really** M9 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/reorganized by row subject and evidence boundary; current occurrence docs/mysql/02-isolation/snapshots-and-the-four-levels.md## Snapshots & the four levels/table.row@18.cell[1] at docs/mysql/02-isolation/snapshots-and-the-four-levels.md:18; current occurrence docs/mysql/02-isolation/snapshots-and-the-four-levels.md## Snapshots & the four levels/table.row@18.cell[2] at docs/mysql/02-isolation/snapshots-and-the-four-levels.md:18 C00207 base docs/mysql/02-isolation/snapshots-and-the-four-levels.md:13 docs/mysql/02-isolation/snapshots-and-the-four-levels.md## Snapshots & the four levels/table.row@13.cell[2] catalog-cell yes M9 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/reorganized by row subject and evidence boundary; current occurrence docs/mysql/02-isolation/snapshots-and-the-four-levels.md## Snapshots & the four levels/table.row@18.cell[1] at docs/mysql/02-isolation/snapshots-and-the-four-levels.md:18; current occurrence docs/mysql/02-isolation/snapshots-and-the-four-levels.md## Snapshots & the four levels/table.row@18.cell[2] at docs/mysql/02-isolation/snapshots-and-the-four-levels.md:18 C00208 base docs/mysql/02-isolation/snapshots-and-the-four-levels.md:13 docs/mysql/02-isolation/snapshots-and-the-four-levels.md## Snapshots & the four levels/table.row@13.cell[3] catalog-cell yes M9 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/reorganized by row subject and evidence boundary; current occurrence docs/mysql/02-isolation/snapshots-and-the-four-levels.md## Snapshots & the four levels/table.row@18.cell[1] at docs/mysql/02-isolation/snapshots-and-the-four-levels.md:18; current occurrence docs/mysql/02-isolation/snapshots-and-the-four-levels.md## Snapshots & the four levels/table.row@18.cell[2] at docs/mysql/02-isolation/snapshots-and-the-four-levels.md:18 C02324 base docs/mysql/02-isolation/snapshots-and-the-four-levels.md:13 docs/mysql/02-isolation/snapshots-and-the-four-levels.md## Snapshots & the four levels/table.row@13.cell[4] catalog-cell none: reads see uncommitted data M9 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/reorganized by row subject and evidence boundary; current occurrence docs/mysql/02-isolation/snapshots-and-the-four-levels.md## Snapshots & the four levels/table.row@18.cell[1] at docs/mysql/02-isolation/snapshots-and-the-four-levels.md:18; current occurrence docs/mysql/02-isolation/snapshots-and-the-four-levels.md## Snapshots & the four levels/table.row@18.cell[2] at docs/mysql/02-isolation/snapshots-and-the-four-levels.md:18 C00209 base docs/mysql/02-isolation/snapshots-and-the-four-levels.md:14 docs/mysql/02-isolation/snapshots-and-the-four-levels.md## Snapshots & the four levels/table.row@14.cell[0] catalog-cell READ COMMITTED M9 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Retained with scoped support; current occurrence docs/mysql/02-isolation/snapshots-and-the-four-levels.md## Snapshots & the four levels/table.row@19.cell[0] at docs/mysql/02-isolation/snapshots-and-the-four-levels.md:19 C00210 base docs/mysql/02-isolation/snapshots-and-the-four-levels.md:14 docs/mysql/02-isolation/snapshots-and-the-four-levels.md## Snapshots & the four levels/table.row@14.cell[1] catalog-cell no M9 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/reorganized by row subject and evidence boundary; current occurrence docs/mysql/02-isolation/snapshots-and-the-four-levels.md## Snapshots & the four levels/table.row@19.cell[1] at docs/mysql/02-isolation/snapshots-and-the-four-levels.md:19; current occurrence docs/mysql/02-isolation/snapshots-and-the-four-levels.md## Snapshots & the four levels/table.row@19.cell[2] at docs/mysql/02-isolation/snapshots-and-the-four-levels.md:19 C00211 base docs/mysql/02-isolation/snapshots-and-the-four-levels.md:14 docs/mysql/02-isolation/snapshots-and-the-four-levels.md## Snapshots & the four levels/table.row@14.cell[2] catalog-cell yes M9 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/reorganized by row subject and evidence boundary; current occurrence docs/mysql/02-isolation/snapshots-and-the-four-levels.md## Snapshots & the four levels/table.row@19.cell[1] at docs/mysql/02-isolation/snapshots-and-the-four-levels.md:19; current occurrence docs/mysql/02-isolation/snapshots-and-the-four-levels.md## Snapshots & the four levels/table.row@19.cell[2] at docs/mysql/02-isolation/snapshots-and-the-four-levels.md:19 C00212 base docs/mysql/02-isolation/snapshots-and-the-four-levels.md:14 docs/mysql/02-isolation/snapshots-and-the-four-levels.md## Snapshots & the four levels/table.row@14.cell[3] catalog-cell yes M9 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/reorganized by row subject and evidence boundary; current occurrence docs/mysql/02-isolation/snapshots-and-the-four-levels.md## Snapshots & the four levels/table.row@19.cell[1] at docs/mysql/02-isolation/snapshots-and-the-four-levels.md:19; current occurrence docs/mysql/02-isolation/snapshots-and-the-four-levels.md## Snapshots & the four levels/table.row@19.cell[2] at docs/mysql/02-isolation/snapshots-and-the-four-levels.md:19 C02325 base docs/mysql/02-isolation/snapshots-and-the-four-levels.md:14 docs/mysql/02-isolation/snapshots-and-the-four-levels.md## Snapshots & the four levels/table.row@14.cell[4] catalog-cell fresh snapshot **per statement** M9 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/reorganized by row subject and evidence boundary; current occurrence docs/mysql/02-isolation/snapshots-and-the-four-levels.md## Snapshots & the four levels/table.row@19.cell[1] at docs/mysql/02-isolation/snapshots-and-the-four-levels.md:19; current occurrence docs/mysql/02-isolation/snapshots-and-the-four-levels.md## Snapshots & the four levels/table.row@19.cell[2] at docs/mysql/02-isolation/snapshots-and-the-four-levels.md:19 C00213 base docs/mysql/02-isolation/snapshots-and-the-four-levels.md:15 docs/mysql/02-isolation/snapshots-and-the-four-levels.md## Snapshots & the four levels/table.row@15.cell[0] catalog-cell REPEATABLE READ *(default)* M9 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/reorganized by row subject and evidence boundary; current occurrence docs/mysql/02-isolation/snapshots-and-the-four-levels.md## Snapshots & the four levels/table.row@20.cell[0] at docs/mysql/02-isolation/snapshots-and-the-four-levels.md:20 C00214 base docs/mysql/02-isolation/snapshots-and-the-four-levels.md:15 docs/mysql/02-isolation/snapshots-and-the-four-levels.md## Snapshots & the four levels/table.row@15.cell[1] catalog-cell no M9 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/reorganized by row subject and evidence boundary; current occurrence docs/mysql/02-isolation/snapshots-and-the-four-levels.md## Snapshots & the four levels/table.row@20.cell[1] at docs/mysql/02-isolation/snapshots-and-the-four-levels.md:20; current occurrence docs/mysql/02-isolation/snapshots-and-the-four-levels.md## Snapshots & the four levels/table.row@20.cell[2] at docs/mysql/02-isolation/snapshots-and-the-four-levels.md:20 C00215 base docs/mysql/02-isolation/snapshots-and-the-four-levels.md:15 docs/mysql/02-isolation/snapshots-and-the-four-levels.md## Snapshots & the four levels/table.row@15.cell[2] catalog-cell no M9 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/reorganized by row subject and evidence boundary; current occurrence docs/mysql/02-isolation/snapshots-and-the-four-levels.md## Snapshots & the four levels/table.row@20.cell[1] at docs/mysql/02-isolation/snapshots-and-the-four-levels.md:20; current occurrence docs/mysql/02-isolation/snapshots-and-the-four-levels.md## Snapshots & the four levels/table.row@20.cell[2] at docs/mysql/02-isolation/snapshots-and-the-four-levels.md:20 C00216 base docs/mysql/02-isolation/snapshots-and-the-four-levels.md:15 docs/mysql/02-isolation/snapshots-and-the-four-levels.md## Snapshots & the four levels/table.row@15.cell[3] catalog-cell no* M9 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/reorganized by row subject and evidence boundary; current occurrence docs/mysql/02-isolation/snapshots-and-the-four-levels.md## Snapshots & the four levels/table.row@20.cell[1] at docs/mysql/02-isolation/snapshots-and-the-four-levels.md:20; current occurrence docs/mysql/02-isolation/snapshots-and-the-four-levels.md## Snapshots & the four levels/table.row@20.cell[2] at docs/mysql/02-isolation/snapshots-and-the-four-levels.md:20 C02326 base docs/mysql/02-isolation/snapshots-and-the-four-levels.md:15 docs/mysql/02-isolation/snapshots-and-the-four-levels.md## Snapshots & the four levels/table.row@15.cell[4] catalog-cell one snapshot **per transaction** M9 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/reorganized by row subject and evidence boundary; current occurrence docs/mysql/02-isolation/snapshots-and-the-four-levels.md## Snapshots & the four levels/table.row@20.cell[1] at docs/mysql/02-isolation/snapshots-and-the-four-levels.md:20; current occurrence docs/mysql/02-isolation/snapshots-and-the-four-levels.md## Snapshots & the four levels/table.row@20.cell[2] at docs/mysql/02-isolation/snapshots-and-the-four-levels.md:20 C00217 base docs/mysql/02-isolation/snapshots-and-the-four-levels.md:16 docs/mysql/02-isolation/snapshots-and-the-four-levels.md## Snapshots & the four levels/table.row@16.cell[0] catalog-cell SERIALIZABLE M9 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Retained with scoped support; current occurrence docs/mysql/02-isolation/snapshots-and-the-four-levels.md## Snapshots & the four levels/table.row@21.cell[0] at docs/mysql/02-isolation/snapshots-and-the-four-levels.md:21 C00218 base docs/mysql/02-isolation/snapshots-and-the-four-levels.md:16 docs/mysql/02-isolation/snapshots-and-the-four-levels.md## Snapshots & the four levels/table.row@16.cell[1] catalog-cell no M9 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/reorganized by row subject and evidence boundary; current occurrence docs/mysql/02-isolation/snapshots-and-the-four-levels.md## Snapshots & the four levels/table.row@21.cell[1] at docs/mysql/02-isolation/snapshots-and-the-four-levels.md:21; current occurrence docs/mysql/02-isolation/snapshots-and-the-four-levels.md## Snapshots & the four levels/table.row@21.cell[2] at docs/mysql/02-isolation/snapshots-and-the-four-levels.md:21 C00219 base docs/mysql/02-isolation/snapshots-and-the-four-levels.md:16 docs/mysql/02-isolation/snapshots-and-the-four-levels.md## Snapshots & the four levels/table.row@16.cell[2] catalog-cell no M9 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/reorganized by row subject and evidence boundary; current occurrence docs/mysql/02-isolation/snapshots-and-the-four-levels.md## Snapshots & the four levels/table.row@21.cell[1] at docs/mysql/02-isolation/snapshots-and-the-four-levels.md:21; current occurrence docs/mysql/02-isolation/snapshots-and-the-four-levels.md## Snapshots & the four levels/table.row@21.cell[2] at docs/mysql/02-isolation/snapshots-and-the-four-levels.md:21 C00220 base docs/mysql/02-isolation/snapshots-and-the-four-levels.md:16 docs/mysql/02-isolation/snapshots-and-the-four-levels.md## Snapshots & the four levels/table.row@16.cell[3] catalog-cell no M9 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/reorganized by row subject and evidence boundary; current occurrence docs/mysql/02-isolation/snapshots-and-the-four-levels.md## Snapshots & the four levels/table.row@21.cell[1] at docs/mysql/02-isolation/snapshots-and-the-four-levels.md:21; current occurrence docs/mysql/02-isolation/snapshots-and-the-four-levels.md## Snapshots & the four levels/table.row@21.cell[2] at docs/mysql/02-isolation/snapshots-and-the-four-levels.md:21 C02327 base docs/mysql/02-isolation/snapshots-and-the-four-levels.md:16 docs/mysql/02-isolation/snapshots-and-the-four-levels.md## Snapshots & the four levels/table.row@16.cell[4] catalog-cell RR + plain SELECTs take [shared locks](/mysql/02-isolation/serializable) M9 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/reorganized by row subject and evidence boundary; current occurrence docs/mysql/02-isolation/snapshots-and-the-four-levels.md## Snapshots & the four levels/table.row@21.cell[1] at docs/mysql/02-isolation/snapshots-and-the-four-levels.md:21; current occurrence docs/mysql/02-isolation/snapshots-and-the-four-levels.md## Snapshots & the four levels/table.row@21.cell[2] at docs/mysql/02-isolation/snapshots-and-the-four-levels.md:21 C00221 base docs/mysql/02-isolation/snapshots-and-the-four-levels.md:18 docs/mysql/02-isolation/snapshots-and-the-four-levels.md## Snapshots & the four levels/paragraph@18 lesson-unit \* for plain SELECTs; [locking reads and writes see the current data](/mysql/02-isolation/repeatable-read). That asterisk is the most important character in this table. M9 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/removed; corrected current source in docs/mysql/02-isolation/snapshots-and-the-four-levels.md, see semantic decisions A1-A10 C00222 base docs/mysql/02-isolation/snapshots-and-the-four-levels.md:20 docs/mysql/02-isolation/snapshots-and-the-four-levels.md## Snapshots & the four levels/paragraph@20 lesson-unit Two things to notice before the demos. MySQL's default is REPEATABLE READ, not READ COMMITTED like PostgreSQL, Oracle, and SQL Server, so most of what your MySQL app does runs at RR. And you set the level with a separate statement: `SET TRANSACTION ISOLATION LEVEL …` for the next transaction only, or `SET SESSION TRANSACTION ISOLATION LEVEL …` for the whole session; there is no `BEGIN ISOLATION LEVEL …` one-liner. M9 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/removed; corrected current source in docs/mysql/02-isolation/snapshots-and-the-four-levels.md, see semantic decisions A1-A10 C00223 base docs/mysql/02-isolation/snapshots-and-the-four-levels.md:26 docs/mysql/02-isolation/snapshots-and-the-four-levels.md### READ UNCOMMITTED means it/line@26 lesson-unit ## READ UNCOMMITTED means it M9 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Retained with scoped support; current occurrence docs/mysql/02-isolation/snapshots-and-the-four-levels.md### READ UNCOMMITTED means it/line@33 at docs/mysql/02-isolation/snapshots-and-the-four-levels.md:33 C00224 base docs/mysql/02-isolation/snapshots-and-the-four-levels.md:28 docs/mysql/02-isolation/snapshots-and-the-four-levels.md### READ UNCOMMITTED means it/paragraph@28 lesson-unit PostgreSQL accepts the READ UNCOMMITTED syntax but silently upgrades it to READ COMMITTED. MySQL takes you at your word, and hands you data that was never committed: M9 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/removed; corrected current source in docs/mysql/02-isolation/snapshots-and-the-four-levels.md, see semantic decisions A1-A10 C00225 base docs/mysql/02-isolation/snapshots-and-the-four-levels.md:31 docs/mysql/02-isolation/snapshots-and-the-four-levels.md### READ UNCOMMITTED means it/line@31 lesson-unit M9 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Retained with scoped support; current occurrence docs/mysql/02-isolation/snapshots-and-the-four-levels.md### READ UNCOMMITTED means it/line@39 at docs/mysql/02-isolation/snapshots-and-the-four-levels.md:39 C00226 base docs/mysql/02-isolation/snapshots-and-the-four-levels.md:33 docs/mysql/02-isolation/snapshots-and-the-four-levels.md### READ UNCOMMITTED means it/paragraph@33 lesson-unit There is no good reason to run at this level: the 999 that B read (and might have acted on) never existed. M9 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/removed; corrected current source in docs/mysql/02-isolation/snapshots-and-the-four-levels.md, see semantic decisions A1-A10 C00227 base docs/mysql/02-isolation/snapshots-and-the-four-levels.md:36 docs/mysql/02-isolation/snapshots-and-the-four-levels.md### READ UNCOMMITTED means it/paragraph@36 lesson-unit Isolation is a per-transaction setting: the server default of REPEATABLE READ can be overridden per session or per transaction, and READ UNCOMMITTED really does hand you dirty reads where [PostgreSQL's](/postgres/02-isolation/snapshots-and-the-four-levels) never would. From here the chapter walks up the ladder ([READ COMMITTED](/mysql/02-isolation/read-committed), [REPEATABLE READ](/mysql/02-isolation/repeatable-read), [SERIALIZABLE](/mysql/02-isolation/serializable)) before landing on the [lost update](/mysql/02-isolation/lost-update), the anomaly your app most likely has today. M9 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/removed; corrected current source in docs/mysql/02-isolation/snapshots-and-the-four-levels.md, see semantic decisions A1-A10 C00228 base docs/mysql/02-isolation/snapshots-and-the-four-levels.md:44 docs/mysql/02-isolation/snapshots-and-the-four-levels.md### Further reading/line@44 lesson-unit ## Further reading M9 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Retained with scoped support; current occurrence docs/mysql/02-isolation/snapshots-and-the-four-levels.md### Further reading/line@49 at docs/mysql/02-isolation/snapshots-and-the-four-levels.md:49 C00229 base docs/mysql/02-isolation/snapshots-and-the-four-levels.md:46 docs/mysql/02-isolation/snapshots-and-the-four-levels.md### Further reading/paragraph@46 lesson-unit - [MySQL docs: Transaction Isolation Levels](https://dev.mysql.com/doc/refman/8.4/en/innodb-transaction-isolation-levels.html) - [MySQL docs: Consistent Nonlocking Reads](https://dev.mysql.com/doc/refman/8.4/en/innodb-consistent-read.html) - [The same lesson on PostgreSQL](/postgres/02-isolation/snapshots-and-the-four-levels) M9 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Replaced/removed; corrected current source in docs/mysql/02-isolation/snapshots-and-the-four-levels.md, see semantic decisions A1-A10 C00230 base scenarios/mysql/01-basics/aborted-transaction.yaml:1 scenarios/mysql/01-basics/aborted-transaction.yaml#title title An error does NOT abort the transaction M10 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Replaced at the corresponding logical occurrence; current occurrence scenarios/mysql/01-basics/aborted-transaction.yaml#title at scenarios/mysql/01-basics/aborted-transaction.yaml:1 C00231 base scenarios/mysql/01-basics/aborted-transaction.yaml:2 scenarios/mysql/01-basics/aborted-transaction.yaml#claim claim After an error inside a transaction, MySQL keeps the transaction alive — only the failed statement is rolled back, and everything else commits normally. M10 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Replaced at the corresponding logical occurrence; current occurrence scenarios/mysql/01-basics/aborted-transaction.yaml#claim at scenarios/mysql/01-basics/aborted-transaction.yaml:2 C00232 base scenarios/mysql/01-basics/aborted-transaction.yaml:6 scenarios/mysql/01-basics/aborted-transaction.yaml#setup setup "CREATE TABLE items (id int PRIMARY KEY, name varchar(50) NOT NULL UNIQUE); INSERT INTO items VALUES (1, 'widget'); " M10 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Replaced at the corresponding logical occurrence; current occurrence scenarios/mysql/01-basics/aborted-transaction.yaml#setup at scenarios/mysql/01-basics/aborted-transaction.yaml:6 C00233 base scenarios/mysql/01-basics/aborted-transaction.yaml:9 scenarios/mysql/01-basics/aborted-transaction.yaml#sessions[0] sessions[0] A M10 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/01-basics/aborted-transaction.yaml#sessions[0] at scenarios/mysql/01-basics/aborted-transaction.yaml:9 C00234 base scenarios/mysql/01-basics/aborted-transaction.yaml:11 scenarios/mysql/01-basics/aborted-transaction.yaml#steps[0].A A BEGIN M10 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/01-basics/aborted-transaction.yaml#steps[0].A at scenarios/mysql/01-basics/aborted-transaction.yaml:11 C00235 base scenarios/mysql/01-basics/aborted-transaction.yaml:12 scenarios/mysql/01-basics/aborted-transaction.yaml#steps[1].A A INSERT INTO items VALUES (2, 'gadget') M10 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/01-basics/aborted-transaction.yaml#steps[1].A at scenarios/mysql/01-basics/aborted-transaction.yaml:12 C00236 base scenarios/mysql/01-basics/aborted-transaction.yaml:14 scenarios/mysql/01-basics/aborted-transaction.yaml#steps[2].A.fails fails INSERT INTO items VALUES (3, 'widget') M10 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/01-basics/aborted-transaction.yaml#steps[2].A.fails at scenarios/mysql/01-basics/aborted-transaction.yaml:14 C00237 base scenarios/mysql/01-basics/aborted-transaction.yaml:15 scenarios/mysql/01-basics/aborted-transaction.yaml#steps[2].error error 1062 M10 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/01-basics/aborted-transaction.yaml#steps[2].error at scenarios/mysql/01-basics/aborted-transaction.yaml:15 C00238 base scenarios/mysql/01-basics/aborted-transaction.yaml:16 scenarios/mysql/01-basics/aborted-transaction.yaml#steps[2].comment comment ER_DUP_ENTRY M10 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/01-basics/aborted-transaction.yaml#steps[2].comment at scenarios/mysql/01-basics/aborted-transaction.yaml:16 C00239 base scenarios/mysql/01-basics/aborted-transaction.yaml:18 scenarios/mysql/01-basics/aborted-transaction.yaml#steps[3].note note PostgreSQL would now refuse every statement until ROLLBACK. MySQL just carries on. M10 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Replaced at the corresponding logical occurrence; current occurrence scenarios/mysql/01-basics/aborted-transaction.yaml#steps[3].note at scenarios/mysql/01-basics/aborted-transaction.yaml:18 C00240 base scenarios/mysql/01-basics/aborted-transaction.yaml:19 scenarios/mysql/01-basics/aborted-transaction.yaml#steps[4].A A INSERT INTO items VALUES (3, 'doohickey') M10 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/01-basics/aborted-transaction.yaml#steps[4].A at scenarios/mysql/01-basics/aborted-transaction.yaml:19 C00241 base scenarios/mysql/01-basics/aborted-transaction.yaml:20 scenarios/mysql/01-basics/aborted-transaction.yaml#steps[5].A A COMMIT M10 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/01-basics/aborted-transaction.yaml#steps[5].A at scenarios/mysql/01-basics/aborted-transaction.yaml:20 C00242 base scenarios/mysql/01-basics/aborted-transaction.yaml:22 scenarios/mysql/01-basics/aborted-transaction.yaml#steps[6].A A SELECT id, name FROM items ORDER BY id M10 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/01-basics/aborted-transaction.yaml#steps[6].A at scenarios/mysql/01-basics/aborted-transaction.yaml:22 C00243 base scenarios/mysql/01-basics/aborted-transaction.yaml:24 scenarios/mysql/01-basics/aborted-transaction.yaml#steps[6].expect[0].id id 1 M10 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/01-basics/aborted-transaction.yaml#steps[6].expect[0].id at scenarios/mysql/01-basics/aborted-transaction.yaml:24 C00244 base scenarios/mysql/01-basics/aborted-transaction.yaml:24 scenarios/mysql/01-basics/aborted-transaction.yaml#steps[6].expect[0].name name widget M10 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/01-basics/aborted-transaction.yaml#steps[6].expect[0].name at scenarios/mysql/01-basics/aborted-transaction.yaml:24 C00245 base scenarios/mysql/01-basics/aborted-transaction.yaml:25 scenarios/mysql/01-basics/aborted-transaction.yaml#steps[6].expect[1].id id 2 M10 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/01-basics/aborted-transaction.yaml#steps[6].expect[1].id at scenarios/mysql/01-basics/aborted-transaction.yaml:25 C00246 base scenarios/mysql/01-basics/aborted-transaction.yaml:25 scenarios/mysql/01-basics/aborted-transaction.yaml#steps[6].expect[1].name name gadget M10 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/01-basics/aborted-transaction.yaml#steps[6].expect[1].name at scenarios/mysql/01-basics/aborted-transaction.yaml:25 C00247 base scenarios/mysql/01-basics/aborted-transaction.yaml:26 scenarios/mysql/01-basics/aborted-transaction.yaml#steps[6].expect[2].id id 3 M10 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/01-basics/aborted-transaction.yaml#steps[6].expect[2].id at scenarios/mysql/01-basics/aborted-transaction.yaml:26 C00248 base scenarios/mysql/01-basics/aborted-transaction.yaml:26 scenarios/mysql/01-basics/aborted-transaction.yaml#steps[6].expect[2].name name doohickey M10 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/01-basics/aborted-transaction.yaml#steps[6].expect[2].name at scenarios/mysql/01-basics/aborted-transaction.yaml:26 C00249 base scenarios/mysql/01-basics/aborted-transaction.yaml:27 scenarios/mysql/01-basics/aborted-transaction.yaml#steps[6].comment comment survived the error in the middle M10 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/01-basics/aborted-transaction.yaml#steps[6].comment at scenarios/mysql/01-basics/aborted-transaction.yaml:27 C00250 base scenarios/mysql/01-basics/atomicity.yaml:1 scenarios/mysql/01-basics/atomicity.yaml#title title Atomicity: all or nothing M11 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/01-basics/atomicity.yaml#title at scenarios/mysql/01-basics/atomicity.yaml:1 C00251 base scenarios/mysql/01-basics/atomicity.yaml:2 scenarios/mysql/01-basics/atomicity.yaml#claim claim A transaction that fails halfway leaves zero partial writes — even statements that already succeeded inside it are undone. M11 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Replaced at the corresponding logical occurrence; current occurrence scenarios/mysql/01-basics/atomicity.yaml#claim at scenarios/mysql/01-basics/atomicity.yaml:2 C00252 base scenarios/mysql/01-basics/atomicity.yaml:5 scenarios/mysql/01-basics/atomicity.yaml#setup setup "CREATE TABLE accounts ( id int PRIMARY KEY, owner varchar(20) NOT NULL, balance int NOT NULL CHECK (balance >= 0) ); INSERT INTO accounts VALUES (1, 'alice', 100), (2, 'bob', 50); " M11 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Replaced at the corresponding logical occurrence; current occurrence scenarios/mysql/01-basics/atomicity.yaml#setup at scenarios/mysql/01-basics/atomicity.yaml:5 C00253 base scenarios/mysql/01-basics/atomicity.yaml:12 scenarios/mysql/01-basics/atomicity.yaml#sessions[0] sessions[0] A M11 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/01-basics/atomicity.yaml#sessions[0] at scenarios/mysql/01-basics/atomicity.yaml:12 C00254 base scenarios/mysql/01-basics/atomicity.yaml:12 scenarios/mysql/01-basics/atomicity.yaml#sessions[1] sessions[1] B M11 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/01-basics/atomicity.yaml#sessions[1] at scenarios/mysql/01-basics/atomicity.yaml:12 C00255 base scenarios/mysql/01-basics/atomicity.yaml:14 scenarios/mysql/01-basics/atomicity.yaml#steps[0].note note A transfers 150 from alice to bob. Crediting bob works fine… M11 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/01-basics/atomicity.yaml#steps[0].note at scenarios/mysql/01-basics/atomicity.yaml:14 C00256 base scenarios/mysql/01-basics/atomicity.yaml:15 scenarios/mysql/01-basics/atomicity.yaml#steps[1].A A BEGIN M11 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/01-basics/atomicity.yaml#steps[1].A at scenarios/mysql/01-basics/atomicity.yaml:15 C00257 base scenarios/mysql/01-basics/atomicity.yaml:16 scenarios/mysql/01-basics/atomicity.yaml#steps[2].A A UPDATE accounts SET balance = balance + 150 WHERE owner = 'bob' M11 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/01-basics/atomicity.yaml#steps[2].A at scenarios/mysql/01-basics/atomicity.yaml:16 C00258 base scenarios/mysql/01-basics/atomicity.yaml:17 scenarios/mysql/01-basics/atomicity.yaml#steps[2].tl tl credit bob +150 (uncommitted) M11 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/01-basics/atomicity.yaml#steps[2].tl at scenarios/mysql/01-basics/atomicity.yaml:17 C00259 base scenarios/mysql/01-basics/atomicity.yaml:19 scenarios/mysql/01-basics/atomicity.yaml#steps[3].B B SELECT balance FROM accounts WHERE owner = 'bob' M11 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/01-basics/atomicity.yaml#steps[3].B at scenarios/mysql/01-basics/atomicity.yaml:19 C00260 base scenarios/mysql/01-basics/atomicity.yaml:20 scenarios/mysql/01-basics/atomicity.yaml#steps[3].expect[0].balance balance 50 M11 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/01-basics/atomicity.yaml#steps[3].expect[0].balance at scenarios/mysql/01-basics/atomicity.yaml:20 C00261 base scenarios/mysql/01-basics/atomicity.yaml:21 scenarios/mysql/01-basics/atomicity.yaml#steps[3].comment comment B can't see A's uncommitted credit M11 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/01-basics/atomicity.yaml#steps[3].comment at scenarios/mysql/01-basics/atomicity.yaml:21 C00262 base scenarios/mysql/01-basics/atomicity.yaml:22 scenarios/mysql/01-basics/atomicity.yaml#steps[3].tl tl read bob → 50 (credit hidden) M11 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/01-basics/atomicity.yaml#steps[3].tl at scenarios/mysql/01-basics/atomicity.yaml:22 C00263 base scenarios/mysql/01-basics/atomicity.yaml:24 scenarios/mysql/01-basics/atomicity.yaml#steps[4].note note …but debiting alice violates the CHECK constraint — she only has 100. M11 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Replaced at the corresponding logical occurrence; current occurrence scenarios/mysql/01-basics/atomicity.yaml#steps[4].note at scenarios/mysql/01-basics/atomicity.yaml:24 C00264 base scenarios/mysql/01-basics/atomicity.yaml:25 scenarios/mysql/01-basics/atomicity.yaml#steps[5].A.fails fails UPDATE accounts SET balance = balance - 150 WHERE owner = 'alice' M11 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/01-basics/atomicity.yaml#steps[5].A.fails at scenarios/mysql/01-basics/atomicity.yaml:25 C00265 base scenarios/mysql/01-basics/atomicity.yaml:26 scenarios/mysql/01-basics/atomicity.yaml#steps[5].error error 3819 M11 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/01-basics/atomicity.yaml#steps[5].error at scenarios/mysql/01-basics/atomicity.yaml:26 C00266 base scenarios/mysql/01-basics/atomicity.yaml:27 scenarios/mysql/01-basics/atomicity.yaml#steps[5].comment comment ER_CHECK_CONSTRAINT_VIOLATED M11 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/01-basics/atomicity.yaml#steps[5].comment at scenarios/mysql/01-basics/atomicity.yaml:27 C00267 base scenarios/mysql/01-basics/atomicity.yaml:28 scenarios/mysql/01-basics/atomicity.yaml#steps[5].tl tl debit alice −150 M11 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/01-basics/atomicity.yaml#steps[5].tl at scenarios/mysql/01-basics/atomicity.yaml:28 C00268 base scenarios/mysql/01-basics/atomicity.yaml:30 scenarios/mysql/01-basics/atomicity.yaml#steps[6].note note Roll the transaction back. Bob's credit — which had succeeded — evaporates with it. M11 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Replaced at the corresponding logical occurrence; current occurrence scenarios/mysql/01-basics/atomicity.yaml#steps[6].note at scenarios/mysql/01-basics/atomicity.yaml:30 C00269 base scenarios/mysql/01-basics/atomicity.yaml:31 scenarios/mysql/01-basics/atomicity.yaml#steps[7].A A ROLLBACK M11 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/01-basics/atomicity.yaml#steps[8].A at scenarios/mysql/01-basics/atomicity.yaml:33 C00270 base scenarios/mysql/01-basics/atomicity.yaml:32 scenarios/mysql/01-basics/atomicity.yaml#steps[7].tl tl ROLLBACK — bob's credit gone too M11 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Replaced at the corresponding logical occurrence; current occurrence scenarios/mysql/01-basics/atomicity.yaml#steps[8].tl at scenarios/mysql/01-basics/atomicity.yaml:34 C00271 base scenarios/mysql/01-basics/atomicity.yaml:34 scenarios/mysql/01-basics/atomicity.yaml#steps[8].B B SELECT owner, balance FROM accounts ORDER BY id M11 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/01-basics/atomicity.yaml#steps[9].B at scenarios/mysql/01-basics/atomicity.yaml:36 C00272 base scenarios/mysql/01-basics/atomicity.yaml:36 scenarios/mysql/01-basics/atomicity.yaml#steps[8].expect[0].owner owner alice M11 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/01-basics/atomicity.yaml#steps[9].expect[0].owner at scenarios/mysql/01-basics/atomicity.yaml:38 C00273 base scenarios/mysql/01-basics/atomicity.yaml:36 scenarios/mysql/01-basics/atomicity.yaml#steps[8].expect[0].balance balance 100 M11 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/01-basics/atomicity.yaml#steps[9].expect[0].balance at scenarios/mysql/01-basics/atomicity.yaml:38 C00274 base scenarios/mysql/01-basics/atomicity.yaml:37 scenarios/mysql/01-basics/atomicity.yaml#steps[8].expect[1].owner owner bob M11 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/01-basics/atomicity.yaml#steps[9].expect[1].owner at scenarios/mysql/01-basics/atomicity.yaml:39 C00275 base scenarios/mysql/01-basics/atomicity.yaml:37 scenarios/mysql/01-basics/atomicity.yaml#steps[8].expect[1].balance balance 50 M11 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/01-basics/atomicity.yaml#steps[9].expect[1].balance at scenarios/mysql/01-basics/atomicity.yaml:39 C00276 base scenarios/mysql/01-basics/atomicity.yaml:38 scenarios/mysql/01-basics/atomicity.yaml#steps[8].tl tl read → alice 100, bob 50 (untouched) M11 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/01-basics/atomicity.yaml#steps[9].tl at scenarios/mysql/01-basics/atomicity.yaml:40 C00277 base scenarios/mysql/01-basics/autocommit-visibility.yaml:1 scenarios/mysql/01-basics/autocommit-visibility.yaml#title title Autocommit and visibility M12 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/01-basics/autocommit-visibility.yaml#title at scenarios/mysql/01-basics/autocommit-visibility.yaml:1 C00278 base scenarios/mysql/01-basics/autocommit-visibility.yaml:2 scenarios/mysql/01-basics/autocommit-visibility.yaml#claim claim Without BEGIN, every statement commits instantly and is immediately visible to everyone; inside BEGIN, changes stay private until COMMIT. M12 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Replaced at the corresponding logical occurrence; current occurrence scenarios/mysql/01-basics/autocommit-visibility.yaml#claim at scenarios/mysql/01-basics/autocommit-visibility.yaml:2 C00279 base scenarios/mysql/01-basics/autocommit-visibility.yaml:5 scenarios/mysql/01-basics/autocommit-visibility.yaml#setup setup "CREATE TABLE accounts (id int PRIMARY KEY, owner varchar(20) NOT NULL, balance int NOT NULL); INSERT INTO accounts VALUES (1, 'alice', 100); " M12 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Replaced at the corresponding logical occurrence; current occurrence scenarios/mysql/01-basics/autocommit-visibility.yaml#setup at scenarios/mysql/01-basics/autocommit-visibility.yaml:6 C00280 base scenarios/mysql/01-basics/autocommit-visibility.yaml:8 scenarios/mysql/01-basics/autocommit-visibility.yaml#sessions[0] sessions[0] A M12 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/01-basics/autocommit-visibility.yaml#sessions[0] at scenarios/mysql/01-basics/autocommit-visibility.yaml:9 C00281 base scenarios/mysql/01-basics/autocommit-visibility.yaml:8 scenarios/mysql/01-basics/autocommit-visibility.yaml#sessions[1] sessions[1] B M12 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/01-basics/autocommit-visibility.yaml#sessions[1] at scenarios/mysql/01-basics/autocommit-visibility.yaml:9 C00282 base scenarios/mysql/01-basics/autocommit-visibility.yaml:10 scenarios/mysql/01-basics/autocommit-visibility.yaml#steps[0].note note No BEGIN — the UPDATE is its own transaction, committed the instant it finishes. M12 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Replaced at the corresponding logical occurrence; current occurrence scenarios/mysql/01-basics/autocommit-visibility.yaml#steps[2].note at scenarios/mysql/01-basics/autocommit-visibility.yaml:15 C00283 base scenarios/mysql/01-basics/autocommit-visibility.yaml:11 scenarios/mysql/01-basics/autocommit-visibility.yaml#steps[1].A A UPDATE accounts SET balance = 150 WHERE id = 1 M12 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/01-basics/autocommit-visibility.yaml#steps[3].A at scenarios/mysql/01-basics/autocommit-visibility.yaml:16 C00284 base scenarios/mysql/01-basics/autocommit-visibility.yaml:12 scenarios/mysql/01-basics/autocommit-visibility.yaml#steps[1].tl tl UPDATE balance = 150 (autocommit) M12 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/01-basics/autocommit-visibility.yaml#steps[3].tl at scenarios/mysql/01-basics/autocommit-visibility.yaml:17 C00285 base scenarios/mysql/01-basics/autocommit-visibility.yaml:14 scenarios/mysql/01-basics/autocommit-visibility.yaml#steps[2].B B SELECT balance FROM accounts WHERE id = 1 M12 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/01-basics/autocommit-visibility.yaml#steps[4].B at scenarios/mysql/01-basics/autocommit-visibility.yaml:19 C00286 base scenarios/mysql/01-basics/autocommit-visibility.yaml:15 scenarios/mysql/01-basics/autocommit-visibility.yaml#steps[2].expect[0].balance balance 150 M12 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/01-basics/autocommit-visibility.yaml#steps[4].expect[0].balance at scenarios/mysql/01-basics/autocommit-visibility.yaml:20 C00287 base scenarios/mysql/01-basics/autocommit-visibility.yaml:16 scenarios/mysql/01-basics/autocommit-visibility.yaml#steps[2].comment comment B sees it immediately M12 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/01-basics/autocommit-visibility.yaml#steps[4].comment at scenarios/mysql/01-basics/autocommit-visibility.yaml:21 C00288 base scenarios/mysql/01-basics/autocommit-visibility.yaml:17 scenarios/mysql/01-basics/autocommit-visibility.yaml#steps[2].tl tl SELECT balance → 150 (visible at once) M12 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/01-basics/autocommit-visibility.yaml#steps[4].tl at scenarios/mysql/01-basics/autocommit-visibility.yaml:22 C00289 base scenarios/mysql/01-basics/autocommit-visibility.yaml:19 scenarios/mysql/01-basics/autocommit-visibility.yaml#steps[3].note note Inside an explicit transaction, A's change is invisible to B… M12 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/01-basics/autocommit-visibility.yaml#steps[5].note at scenarios/mysql/01-basics/autocommit-visibility.yaml:24 C00290 base scenarios/mysql/01-basics/autocommit-visibility.yaml:20 scenarios/mysql/01-basics/autocommit-visibility.yaml#steps[4].A A BEGIN M12 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/01-basics/autocommit-visibility.yaml#steps[6].A at scenarios/mysql/01-basics/autocommit-visibility.yaml:25 C00291 base scenarios/mysql/01-basics/autocommit-visibility.yaml:21 scenarios/mysql/01-basics/autocommit-visibility.yaml#steps[5].A A UPDATE accounts SET balance = 999 WHERE id = 1 M12 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/01-basics/autocommit-visibility.yaml#steps[7].A at scenarios/mysql/01-basics/autocommit-visibility.yaml:26 C00292 base scenarios/mysql/01-basics/autocommit-visibility.yaml:22 scenarios/mysql/01-basics/autocommit-visibility.yaml#steps[5].tl tl UPDATE balance = 999 (uncommitted) M12 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/01-basics/autocommit-visibility.yaml#steps[7].tl at scenarios/mysql/01-basics/autocommit-visibility.yaml:27 C00293 base scenarios/mysql/01-basics/autocommit-visibility.yaml:24 scenarios/mysql/01-basics/autocommit-visibility.yaml#steps[6].B B SELECT balance FROM accounts WHERE id = 1 M12 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/01-basics/autocommit-visibility.yaml#steps[8].B at scenarios/mysql/01-basics/autocommit-visibility.yaml:29 C00294 base scenarios/mysql/01-basics/autocommit-visibility.yaml:25 scenarios/mysql/01-basics/autocommit-visibility.yaml#steps[6].expect[0].balance balance 150 M12 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/01-basics/autocommit-visibility.yaml#steps[8].expect[0].balance at scenarios/mysql/01-basics/autocommit-visibility.yaml:30 C00295 base scenarios/mysql/01-basics/autocommit-visibility.yaml:26 scenarios/mysql/01-basics/autocommit-visibility.yaml#steps[6].comment comment still the old value M12 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/01-basics/autocommit-visibility.yaml#steps[8].comment at scenarios/mysql/01-basics/autocommit-visibility.yaml:31 C00296 base scenarios/mysql/01-basics/autocommit-visibility.yaml:27 scenarios/mysql/01-basics/autocommit-visibility.yaml#steps[6].tl tl SELECT balance → 150 (A's change hidden) M12 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/01-basics/autocommit-visibility.yaml#steps[8].tl at scenarios/mysql/01-basics/autocommit-visibility.yaml:32 C00297 base scenarios/mysql/01-basics/autocommit-visibility.yaml:29 scenarios/mysql/01-basics/autocommit-visibility.yaml#steps[7].note note …until A commits. M12 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Replaced at the corresponding logical occurrence; current occurrence scenarios/mysql/01-basics/autocommit-visibility.yaml#steps[9].note at scenarios/mysql/01-basics/autocommit-visibility.yaml:34 C00298 base scenarios/mysql/01-basics/autocommit-visibility.yaml:30 scenarios/mysql/01-basics/autocommit-visibility.yaml#steps[8].A A COMMIT M12 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/01-basics/autocommit-visibility.yaml#steps[10].A at scenarios/mysql/01-basics/autocommit-visibility.yaml:35 C00299 base scenarios/mysql/01-basics/autocommit-visibility.yaml:31 scenarios/mysql/01-basics/autocommit-visibility.yaml#steps[8].tl tl COMMIT M12 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/01-basics/autocommit-visibility.yaml#steps[10].tl at scenarios/mysql/01-basics/autocommit-visibility.yaml:36 C00300 base scenarios/mysql/01-basics/autocommit-visibility.yaml:33 scenarios/mysql/01-basics/autocommit-visibility.yaml#steps[9].B B SELECT balance FROM accounts WHERE id = 1 M12 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/01-basics/autocommit-visibility.yaml#steps[11].B at scenarios/mysql/01-basics/autocommit-visibility.yaml:38 C00301 base scenarios/mysql/01-basics/autocommit-visibility.yaml:34 scenarios/mysql/01-basics/autocommit-visibility.yaml#steps[9].expect[0].balance balance 999 M12 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/01-basics/autocommit-visibility.yaml#steps[11].expect[0].balance at scenarios/mysql/01-basics/autocommit-visibility.yaml:39 C00302 base scenarios/mysql/01-basics/autocommit-visibility.yaml:35 scenarios/mysql/01-basics/autocommit-visibility.yaml#steps[9].tl tl SELECT balance → 999 (now visible) M12 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/01-basics/autocommit-visibility.yaml#steps[11].tl at scenarios/mysql/01-basics/autocommit-visibility.yaml:40 C00303 base scenarios/mysql/01-basics/savepoint-nesting.yaml:1 scenarios/mysql/01-basics/savepoint-nesting.yaml#title title Nested savepoints and RELEASE M13 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/01-basics/savepoint-nesting.yaml#title at scenarios/mysql/01-basics/savepoint-nesting.yaml:1 C00304 base scenarios/mysql/01-basics/savepoint-nesting.yaml:2 scenarios/mysql/01-basics/savepoint-nesting.yaml#claim claim Rolling back to an outer savepoint discards inner savepoints along with their work; RELEASE keeps the changes but forfeits the rollback point. M13 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/01-basics/savepoint-nesting.yaml#claim at scenarios/mysql/01-basics/savepoint-nesting.yaml:2 C00305 base scenarios/mysql/01-basics/savepoint-nesting.yaml:5 scenarios/mysql/01-basics/savepoint-nesting.yaml#setup setup "CREATE TABLE steps (n int PRIMARY KEY); " M13 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Replaced at the corresponding logical occurrence; current occurrence scenarios/mysql/01-basics/savepoint-nesting.yaml#setup at scenarios/mysql/01-basics/savepoint-nesting.yaml:5 C00306 base scenarios/mysql/01-basics/savepoint-nesting.yaml:7 scenarios/mysql/01-basics/savepoint-nesting.yaml#sessions[0] sessions[0] A M13 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/01-basics/savepoint-nesting.yaml#sessions[0] at scenarios/mysql/01-basics/savepoint-nesting.yaml:7 C00307 base scenarios/mysql/01-basics/savepoint-nesting.yaml:9 scenarios/mysql/01-basics/savepoint-nesting.yaml#steps[0].A A BEGIN M13 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/01-basics/savepoint-nesting.yaml#steps[0].A at scenarios/mysql/01-basics/savepoint-nesting.yaml:9 C00308 base scenarios/mysql/01-basics/savepoint-nesting.yaml:10 scenarios/mysql/01-basics/savepoint-nesting.yaml#steps[1].A A INSERT INTO steps VALUES (1) M13 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/01-basics/savepoint-nesting.yaml#steps[1].A at scenarios/mysql/01-basics/savepoint-nesting.yaml:10 C00309 base scenarios/mysql/01-basics/savepoint-nesting.yaml:11 scenarios/mysql/01-basics/savepoint-nesting.yaml#steps[2].A A SAVEPOINT outer_sp M13 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/01-basics/savepoint-nesting.yaml#steps[2].A at scenarios/mysql/01-basics/savepoint-nesting.yaml:11 C00310 base scenarios/mysql/01-basics/savepoint-nesting.yaml:12 scenarios/mysql/01-basics/savepoint-nesting.yaml#steps[3].A A INSERT INTO steps VALUES (2) M13 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/01-basics/savepoint-nesting.yaml#steps[3].A at scenarios/mysql/01-basics/savepoint-nesting.yaml:12 C00311 base scenarios/mysql/01-basics/savepoint-nesting.yaml:13 scenarios/mysql/01-basics/savepoint-nesting.yaml#steps[4].A A SAVEPOINT inner_sp M13 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/01-basics/savepoint-nesting.yaml#steps[4].A at scenarios/mysql/01-basics/savepoint-nesting.yaml:13 C00312 base scenarios/mysql/01-basics/savepoint-nesting.yaml:14 scenarios/mysql/01-basics/savepoint-nesting.yaml#steps[5].A A INSERT INTO steps VALUES (3) M13 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/01-basics/savepoint-nesting.yaml#steps[5].A at scenarios/mysql/01-basics/savepoint-nesting.yaml:14 C00313 base scenarios/mysql/01-basics/savepoint-nesting.yaml:16 scenarios/mysql/01-basics/savepoint-nesting.yaml#steps[6].note note Rolling back to the OUTER savepoint discards rows 2 and 3 — and inner_sp itself. M13 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Replaced at the corresponding logical occurrence; current occurrence scenarios/mysql/01-basics/savepoint-nesting.yaml#steps[6].note at scenarios/mysql/01-basics/savepoint-nesting.yaml:16 C00314 base scenarios/mysql/01-basics/savepoint-nesting.yaml:17 scenarios/mysql/01-basics/savepoint-nesting.yaml#steps[7].A A ROLLBACK TO SAVEPOINT outer_sp M13 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/01-basics/savepoint-nesting.yaml#steps[7].A at scenarios/mysql/01-basics/savepoint-nesting.yaml:17 C00315 base scenarios/mysql/01-basics/savepoint-nesting.yaml:19 scenarios/mysql/01-basics/savepoint-nesting.yaml#steps[8].A.fails fails ROLLBACK TO SAVEPOINT inner_sp M13 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/01-basics/savepoint-nesting.yaml#steps[8].A.fails at scenarios/mysql/01-basics/savepoint-nesting.yaml:19 C00316 base scenarios/mysql/01-basics/savepoint-nesting.yaml:20 scenarios/mysql/01-basics/savepoint-nesting.yaml#steps[8].error error 1305 M13 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/01-basics/savepoint-nesting.yaml#steps[8].error at scenarios/mysql/01-basics/savepoint-nesting.yaml:20 C00317 base scenarios/mysql/01-basics/savepoint-nesting.yaml:21 scenarios/mysql/01-basics/savepoint-nesting.yaml#steps[8].comment comment SAVEPOINT inner_sp does not exist — destroyed by the outer rollback M13 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Replaced at the corresponding logical occurrence; current occurrence scenarios/mysql/01-basics/savepoint-nesting.yaml#steps[8].comment at scenarios/mysql/01-basics/savepoint-nesting.yaml:21 C00318 base scenarios/mysql/01-basics/savepoint-nesting.yaml:23 scenarios/mysql/01-basics/savepoint-nesting.yaml#steps[9].note note RELEASE keeps the work done after the savepoint, but you can no longer rewind to it. M13 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/01-basics/savepoint-nesting.yaml#steps[9].note at scenarios/mysql/01-basics/savepoint-nesting.yaml:23 C00319 base scenarios/mysql/01-basics/savepoint-nesting.yaml:24 scenarios/mysql/01-basics/savepoint-nesting.yaml#steps[10].A A INSERT INTO steps VALUES (4) M13 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/01-basics/savepoint-nesting.yaml#steps[10].A at scenarios/mysql/01-basics/savepoint-nesting.yaml:24 C00320 base scenarios/mysql/01-basics/savepoint-nesting.yaml:25 scenarios/mysql/01-basics/savepoint-nesting.yaml#steps[11].A A RELEASE SAVEPOINT outer_sp M13 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/01-basics/savepoint-nesting.yaml#steps[11].A at scenarios/mysql/01-basics/savepoint-nesting.yaml:25 C00321 base scenarios/mysql/01-basics/savepoint-nesting.yaml:26 scenarios/mysql/01-basics/savepoint-nesting.yaml#steps[12].A A COMMIT M13 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/01-basics/savepoint-nesting.yaml#steps[13].A at scenarios/mysql/01-basics/savepoint-nesting.yaml:29 C00322 base scenarios/mysql/01-basics/savepoint-nesting.yaml:28 scenarios/mysql/01-basics/savepoint-nesting.yaml#steps[13].A A SELECT n FROM steps ORDER BY n M13 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/01-basics/savepoint-nesting.yaml#steps[14].A at scenarios/mysql/01-basics/savepoint-nesting.yaml:31 C00323 base scenarios/mysql/01-basics/savepoint-nesting.yaml:29 scenarios/mysql/01-basics/savepoint-nesting.yaml#steps[13].expect[0].n n 1 M13 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/01-basics/savepoint-nesting.yaml#steps[14].expect[0].n at scenarios/mysql/01-basics/savepoint-nesting.yaml:32 C00324 base scenarios/mysql/01-basics/savepoint-nesting.yaml:29 scenarios/mysql/01-basics/savepoint-nesting.yaml#steps[13].expect[1].n n 4 M13 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/01-basics/savepoint-nesting.yaml#steps[14].expect[1].n at scenarios/mysql/01-basics/savepoint-nesting.yaml:32 C00325 base scenarios/mysql/01-basics/savepoint-recovery.yaml:1 scenarios/mysql/01-basics/savepoint-recovery.yaml#title title Savepoints: discard a risky branch mid-transaction M14 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/01-basics/savepoint-recovery.yaml#title at scenarios/mysql/01-basics/savepoint-recovery.yaml:1 C00326 base scenarios/mysql/01-basics/savepoint-recovery.yaml:2 scenarios/mysql/01-basics/savepoint-recovery.yaml#claim claim ROLLBACK TO SAVEPOINT discards only the work done after the savepoint — the rest of the transaction commits normally. M14 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Replaced at the corresponding logical occurrence; current occurrence scenarios/mysql/01-basics/savepoint-recovery.yaml#claim at scenarios/mysql/01-basics/savepoint-recovery.yaml:2 C00327 base scenarios/mysql/01-basics/savepoint-recovery.yaml:5 scenarios/mysql/01-basics/savepoint-recovery.yaml#setup setup "CREATE TABLE items (id int PRIMARY KEY, name varchar(50) NOT NULL UNIQUE); INSERT INTO items VALUES (1, 'widget'); " M14 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Replaced at the corresponding logical occurrence; current occurrence scenarios/mysql/01-basics/savepoint-recovery.yaml#setup at scenarios/mysql/01-basics/savepoint-recovery.yaml:6 C00328 base scenarios/mysql/01-basics/savepoint-recovery.yaml:8 scenarios/mysql/01-basics/savepoint-recovery.yaml#sessions[0] sessions[0] A M14 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/01-basics/savepoint-recovery.yaml#sessions[0] at scenarios/mysql/01-basics/savepoint-recovery.yaml:9 C00329 base scenarios/mysql/01-basics/savepoint-recovery.yaml:10 scenarios/mysql/01-basics/savepoint-recovery.yaml#steps[0].A A BEGIN M14 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/01-basics/savepoint-recovery.yaml#steps[0].A at scenarios/mysql/01-basics/savepoint-recovery.yaml:11 C00330 base scenarios/mysql/01-basics/savepoint-recovery.yaml:11 scenarios/mysql/01-basics/savepoint-recovery.yaml#steps[1].A A INSERT INTO items VALUES (2, 'gadget') M14 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/01-basics/savepoint-recovery.yaml#steps[1].A at scenarios/mysql/01-basics/savepoint-recovery.yaml:12 C00331 base scenarios/mysql/01-basics/savepoint-recovery.yaml:12 scenarios/mysql/01-basics/savepoint-recovery.yaml#steps[2].A A SAVEPOINT before_risky M14 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/01-basics/savepoint-recovery.yaml#steps[2].A at scenarios/mysql/01-basics/savepoint-recovery.yaml:13 C00332 base scenarios/mysql/01-basics/savepoint-recovery.yaml:14 scenarios/mysql/01-basics/savepoint-recovery.yaml#steps[3].note note The risky branch makes real progress before it fails… M14 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/01-basics/savepoint-recovery.yaml#steps[3].note at scenarios/mysql/01-basics/savepoint-recovery.yaml:15 C00333 base scenarios/mysql/01-basics/savepoint-recovery.yaml:15 scenarios/mysql/01-basics/savepoint-recovery.yaml#steps[4].A A INSERT INTO items VALUES (3, 'gizmo') M14 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/01-basics/savepoint-recovery.yaml#steps[4].A at scenarios/mysql/01-basics/savepoint-recovery.yaml:16 C00334 base scenarios/mysql/01-basics/savepoint-recovery.yaml:16 scenarios/mysql/01-basics/savepoint-recovery.yaml#steps[5].A.fails fails INSERT INTO items VALUES (4, 'widget') M14 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/01-basics/savepoint-recovery.yaml#steps[5].A.fails at scenarios/mysql/01-basics/savepoint-recovery.yaml:17 C00335 base scenarios/mysql/01-basics/savepoint-recovery.yaml:17 scenarios/mysql/01-basics/savepoint-recovery.yaml#steps[5].error error 1062 M14 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/01-basics/savepoint-recovery.yaml#steps[5].error at scenarios/mysql/01-basics/savepoint-recovery.yaml:18 C00336 base scenarios/mysql/01-basics/savepoint-recovery.yaml:18 scenarios/mysql/01-basics/savepoint-recovery.yaml#steps[5].comment comment ER_DUP_ENTRY M14 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/01-basics/savepoint-recovery.yaml#steps[5].comment at scenarios/mysql/01-basics/savepoint-recovery.yaml:19 C00337 base scenarios/mysql/01-basics/savepoint-recovery.yaml:20 scenarios/mysql/01-basics/savepoint-recovery.yaml#steps[6].note note The transaction is still alive — but the branch is half-done. Rewind all of it in one go. M14 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Replaced at the corresponding logical occurrence; current occurrence scenarios/mysql/01-basics/savepoint-recovery.yaml#steps[6].note at scenarios/mysql/01-basics/savepoint-recovery.yaml:21 C00338 base scenarios/mysql/01-basics/savepoint-recovery.yaml:21 scenarios/mysql/01-basics/savepoint-recovery.yaml#steps[7].A A ROLLBACK TO SAVEPOINT before_risky M14 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/01-basics/savepoint-recovery.yaml#steps[7].A at scenarios/mysql/01-basics/savepoint-recovery.yaml:22 C00339 base scenarios/mysql/01-basics/savepoint-recovery.yaml:22 scenarios/mysql/01-basics/savepoint-recovery.yaml#steps[8].A A INSERT INTO items VALUES (3, 'doohickey') M14 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/01-basics/savepoint-recovery.yaml#steps[9].A at scenarios/mysql/01-basics/savepoint-recovery.yaml:25 C00340 base scenarios/mysql/01-basics/savepoint-recovery.yaml:23 scenarios/mysql/01-basics/savepoint-recovery.yaml#steps[9].A A COMMIT M14 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/01-basics/savepoint-recovery.yaml#steps[10].A at scenarios/mysql/01-basics/savepoint-recovery.yaml:26 C00341 base scenarios/mysql/01-basics/savepoint-recovery.yaml:25 scenarios/mysql/01-basics/savepoint-recovery.yaml#steps[10].A A SELECT id, name FROM items ORDER BY id M14 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/01-basics/savepoint-recovery.yaml#steps[11].A at scenarios/mysql/01-basics/savepoint-recovery.yaml:28 C00342 base scenarios/mysql/01-basics/savepoint-recovery.yaml:27 scenarios/mysql/01-basics/savepoint-recovery.yaml#steps[10].expect[0].id id 1 M14 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/01-basics/savepoint-recovery.yaml#steps[11].expect[0].id at scenarios/mysql/01-basics/savepoint-recovery.yaml:30 C00343 base scenarios/mysql/01-basics/savepoint-recovery.yaml:27 scenarios/mysql/01-basics/savepoint-recovery.yaml#steps[10].expect[0].name name widget M14 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/01-basics/savepoint-recovery.yaml#steps[11].expect[0].name at scenarios/mysql/01-basics/savepoint-recovery.yaml:30 C00344 base scenarios/mysql/01-basics/savepoint-recovery.yaml:28 scenarios/mysql/01-basics/savepoint-recovery.yaml#steps[10].expect[1].id id 2 M14 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/01-basics/savepoint-recovery.yaml#steps[11].expect[1].id at scenarios/mysql/01-basics/savepoint-recovery.yaml:31 C00345 base scenarios/mysql/01-basics/savepoint-recovery.yaml:28 scenarios/mysql/01-basics/savepoint-recovery.yaml#steps[10].expect[1].name name gadget M14 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/01-basics/savepoint-recovery.yaml#steps[11].expect[1].name at scenarios/mysql/01-basics/savepoint-recovery.yaml:31 C00346 base scenarios/mysql/01-basics/savepoint-recovery.yaml:29 scenarios/mysql/01-basics/savepoint-recovery.yaml#steps[10].expect[2].id id 3 M14 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/01-basics/savepoint-recovery.yaml#steps[11].expect[2].id at scenarios/mysql/01-basics/savepoint-recovery.yaml:32 C00347 base scenarios/mysql/01-basics/savepoint-recovery.yaml:29 scenarios/mysql/01-basics/savepoint-recovery.yaml#steps[10].expect[2].name name doohickey M14 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/01-basics/savepoint-recovery.yaml#steps[11].expect[2].name at scenarios/mysql/01-basics/savepoint-recovery.yaml:32 C00348 base scenarios/mysql/01-basics/savepoint-recovery.yaml:30 scenarios/mysql/01-basics/savepoint-recovery.yaml#steps[10].comment comment survived — it predates the savepoint; 'gizmo' is gone with the branch M14 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Replaced at the corresponding logical occurrence; current occurrence scenarios/mysql/01-basics/savepoint-recovery.yaml#steps[11].comment at scenarios/mysql/01-basics/savepoint-recovery.yaml:33 C00349 base scenarios/mysql/02-isolation/circular-information-flow.yaml:1 scenarios/mysql/02-isolation/circular-information-flow.yaml#title title Circular information flow at READ UNCOMMITTED M15 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/02-isolation/circular-information-flow.yaml#title at scenarios/mysql/02-isolation/circular-information-flow.yaml:1 C00350 base scenarios/mysql/02-isolation/circular-information-flow.yaml:2 scenarios/mysql/02-isolation/circular-information-flow.yaml#claim claim "At READ UNCOMMITTED two concurrent transactions can each read the other's uncommitted write (Adya's G1c, ""circular information flow"") — an exchange no serial order can explain. READ COMMITTED makes it impossible." M15 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Replaced at the corresponding logical occurrence; current occurrence scenarios/mysql/02-isolation/circular-information-flow.yaml#claim at scenarios/mysql/02-isolation/circular-information-flow.yaml:2 C00351 base scenarios/mysql/02-isolation/circular-information-flow.yaml:6 scenarios/mysql/02-isolation/circular-information-flow.yaml#anomaly anomaly G1c M15 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/circular-information-flow.yaml#anomaly at scenarios/mysql/02-isolation/circular-information-flow.yaml:7 C00352 base scenarios/mysql/02-isolation/circular-information-flow.yaml:7 scenarios/mysql/02-isolation/circular-information-flow.yaml#setup setup "CREATE TABLE accounts (id int PRIMARY KEY, owner varchar(20) NOT NULL, balance int NOT NULL); INSERT INTO accounts VALUES (1, 'alice', 100), (2, 'bob', 100); " M15 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Replaced at the corresponding logical occurrence; current occurrence scenarios/mysql/02-isolation/circular-information-flow.yaml#setup at scenarios/mysql/02-isolation/circular-information-flow.yaml:8 C00353 base scenarios/mysql/02-isolation/circular-information-flow.yaml:10 scenarios/mysql/02-isolation/circular-information-flow.yaml#sessions[0] sessions[0] A M15 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/circular-information-flow.yaml#sessions[0] at scenarios/mysql/02-isolation/circular-information-flow.yaml:11 C00354 base scenarios/mysql/02-isolation/circular-information-flow.yaml:10 scenarios/mysql/02-isolation/circular-information-flow.yaml#sessions[1] sessions[1] B M15 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/circular-information-flow.yaml#sessions[1] at scenarios/mysql/02-isolation/circular-information-flow.yaml:11 C00355 base scenarios/mysql/02-isolation/circular-information-flow.yaml:12 scenarios/mysql/02-isolation/circular-information-flow.yaml#steps[0].note note A adjusts alice while B adjusts bob — then each peeks at the other's row. In any serial order, at most one of them can see the other's write. M15 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Replaced at the corresponding logical occurrence; current occurrence scenarios/mysql/02-isolation/circular-information-flow.yaml#steps[0].note at scenarios/mysql/02-isolation/circular-information-flow.yaml:13 C00356 base scenarios/mysql/02-isolation/circular-information-flow.yaml:15 scenarios/mysql/02-isolation/circular-information-flow.yaml#steps[1].A A SET SESSION TRANSACTION ISOLATION LEVEL READ UNCOMMITTED M15 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ UNCOMMITTED, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/circular-information-flow.yaml#steps[1].A at scenarios/mysql/02-isolation/circular-information-flow.yaml:16 C00357 base scenarios/mysql/02-isolation/circular-information-flow.yaml:16 scenarios/mysql/02-isolation/circular-information-flow.yaml#steps[2].B B SET SESSION TRANSACTION ISOLATION LEVEL READ UNCOMMITTED M15 MySQL 8.4.11, InnoDB; before step: A=READ UNCOMMITTED, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ UNCOMMITTED, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/circular-information-flow.yaml#steps[2].B at scenarios/mysql/02-isolation/circular-information-flow.yaml:17 C00358 base scenarios/mysql/02-isolation/circular-information-flow.yaml:17 scenarios/mysql/02-isolation/circular-information-flow.yaml#steps[3].A A BEGIN M15 MySQL 8.4.11, InnoDB; before step: A=READ UNCOMMITTED, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ UNCOMMITTED, open transaction, autocommit=1; B=READ UNCOMMITTED, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/circular-information-flow.yaml#steps[3].A at scenarios/mysql/02-isolation/circular-information-flow.yaml:18 C00359 base scenarios/mysql/02-isolation/circular-information-flow.yaml:18 scenarios/mysql/02-isolation/circular-information-flow.yaml#steps[4].B B BEGIN M15 MySQL 8.4.11, InnoDB; before step: A=READ UNCOMMITTED, open transaction, autocommit=1; B=READ UNCOMMITTED, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ UNCOMMITTED, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/circular-information-flow.yaml#steps[4].B at scenarios/mysql/02-isolation/circular-information-flow.yaml:19 C00360 base scenarios/mysql/02-isolation/circular-information-flow.yaml:19 scenarios/mysql/02-isolation/circular-information-flow.yaml#steps[5].A A UPDATE accounts SET balance = 111 WHERE id = 1 M15 MySQL 8.4.11, InnoDB; before step: A=READ UNCOMMITTED, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=READ UNCOMMITTED, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/circular-information-flow.yaml#steps[5].A at scenarios/mysql/02-isolation/circular-information-flow.yaml:20 C00361 base scenarios/mysql/02-isolation/circular-information-flow.yaml:20 scenarios/mysql/02-isolation/circular-information-flow.yaml#steps[5].tl tl UPDATE alice = 111 (uncommitted) M15 MySQL 8.4.11, InnoDB; before step: A=READ UNCOMMITTED, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=READ UNCOMMITTED, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/02-isolation/circular-information-flow.yaml#steps[5].tl at scenarios/mysql/02-isolation/circular-information-flow.yaml:21 C00362 base scenarios/mysql/02-isolation/circular-information-flow.yaml:21 scenarios/mysql/02-isolation/circular-information-flow.yaml#steps[6].B B UPDATE accounts SET balance = 222 WHERE id = 2 M15 MySQL 8.4.11, InnoDB; before step: A=READ UNCOMMITTED, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=READ UNCOMMITTED, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/circular-information-flow.yaml#steps[6].B at scenarios/mysql/02-isolation/circular-information-flow.yaml:22 C00363 base scenarios/mysql/02-isolation/circular-information-flow.yaml:22 scenarios/mysql/02-isolation/circular-information-flow.yaml#steps[6].tl tl UPDATE bob = 222 (uncommitted) M15 MySQL 8.4.11, InnoDB; before step: A=READ UNCOMMITTED, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=READ UNCOMMITTED, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/02-isolation/circular-information-flow.yaml#steps[6].tl at scenarios/mysql/02-isolation/circular-information-flow.yaml:23 C00364 base scenarios/mysql/02-isolation/circular-information-flow.yaml:24 scenarios/mysql/02-isolation/circular-information-flow.yaml#steps[7].A A SELECT balance FROM accounts WHERE id = 2 M15 MySQL 8.4.11, InnoDB; before step: A=READ UNCOMMITTED, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=READ UNCOMMITTED, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/circular-information-flow.yaml#steps[7].A at scenarios/mysql/02-isolation/circular-information-flow.yaml:25 C00365 base scenarios/mysql/02-isolation/circular-information-flow.yaml:25 scenarios/mysql/02-isolation/circular-information-flow.yaml#steps[7].expect[0].balance balance 222 M15 MySQL 8.4.11, InnoDB; before step: A=READ UNCOMMITTED, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=READ UNCOMMITTED, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/circular-information-flow.yaml#steps[7].expect[0].balance at scenarios/mysql/02-isolation/circular-information-flow.yaml:26 C00366 base scenarios/mysql/02-isolation/circular-information-flow.yaml:26 scenarios/mysql/02-isolation/circular-information-flow.yaml#steps[7].comment comment A sees B's uncommitted write… M15 MySQL 8.4.11, InnoDB; before step: A=READ UNCOMMITTED, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=READ UNCOMMITTED, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/02-isolation/circular-information-flow.yaml#steps[7].comment at scenarios/mysql/02-isolation/circular-information-flow.yaml:27 C00367 base scenarios/mysql/02-isolation/circular-information-flow.yaml:27 scenarios/mysql/02-isolation/circular-information-flow.yaml#steps[7].tl tl read bob → 222 (B's uncommitted) M15 MySQL 8.4.11, InnoDB; before step: A=READ UNCOMMITTED, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=READ UNCOMMITTED, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/02-isolation/circular-information-flow.yaml#steps[7].tl at scenarios/mysql/02-isolation/circular-information-flow.yaml:28 C00368 base scenarios/mysql/02-isolation/circular-information-flow.yaml:28 scenarios/mysql/02-isolation/circular-information-flow.yaml#steps[8].B B SELECT balance FROM accounts WHERE id = 1 M15 MySQL 8.4.11, InnoDB; before step: A=READ UNCOMMITTED, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=READ UNCOMMITTED, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/circular-information-flow.yaml#steps[8].B at scenarios/mysql/02-isolation/circular-information-flow.yaml:29 C00369 base scenarios/mysql/02-isolation/circular-information-flow.yaml:29 scenarios/mysql/02-isolation/circular-information-flow.yaml#steps[8].expect[0].balance balance 111 M15 MySQL 8.4.11, InnoDB; before step: A=READ UNCOMMITTED, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=READ UNCOMMITTED, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/circular-information-flow.yaml#steps[8].expect[0].balance at scenarios/mysql/02-isolation/circular-information-flow.yaml:30 C00370 base scenarios/mysql/02-isolation/circular-information-flow.yaml:30 scenarios/mysql/02-isolation/circular-information-flow.yaml#steps[8].comment comment …and B sees A's. Information flowed in a circle. M15 MySQL 8.4.11, InnoDB; before step: A=READ UNCOMMITTED, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=READ UNCOMMITTED, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/02-isolation/circular-information-flow.yaml#steps[8].comment at scenarios/mysql/02-isolation/circular-information-flow.yaml:31 C00371 base scenarios/mysql/02-isolation/circular-information-flow.yaml:31 scenarios/mysql/02-isolation/circular-information-flow.yaml#steps[8].tl tl read alice → 111 (A's uncommitted) M15 MySQL 8.4.11, InnoDB; before step: A=READ UNCOMMITTED, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=READ UNCOMMITTED, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/02-isolation/circular-information-flow.yaml#steps[8].tl at scenarios/mysql/02-isolation/circular-information-flow.yaml:32 C00372 base scenarios/mysql/02-isolation/circular-information-flow.yaml:33 scenarios/mysql/02-isolation/circular-information-flow.yaml#steps[9].note note Neither value was committed when it was read — if either side now rolls back, the other has computed on data that never existed. Both roll back: M15 MySQL 8.4.11, InnoDB; before step: A=READ UNCOMMITTED, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=READ UNCOMMITTED, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Replaced at the corresponding logical occurrence; current occurrence scenarios/mysql/02-isolation/circular-information-flow.yaml#steps[9].note at scenarios/mysql/02-isolation/circular-information-flow.yaml:34 C00373 base scenarios/mysql/02-isolation/circular-information-flow.yaml:36 scenarios/mysql/02-isolation/circular-information-flow.yaml#steps[10].A A ROLLBACK M15 MySQL 8.4.11, InnoDB; before step: A=READ UNCOMMITTED, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=READ UNCOMMITTED, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Replaced at the corresponding logical occurrence; current occurrence scenarios/mysql/02-isolation/circular-information-flow.yaml#steps[10].A at scenarios/mysql/02-isolation/circular-information-flow.yaml:38 C00374 base scenarios/mysql/02-isolation/circular-information-flow.yaml:37 scenarios/mysql/02-isolation/circular-information-flow.yaml#steps[10].tl tl ROLLBACK M15 MySQL 8.4.11, InnoDB; before step: A=READ UNCOMMITTED, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=READ UNCOMMITTED, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Replaced at the corresponding logical occurrence; current occurrence scenarios/mysql/02-isolation/circular-information-flow.yaml#steps[10].tl at scenarios/mysql/02-isolation/circular-information-flow.yaml:39 C00375 base scenarios/mysql/02-isolation/circular-information-flow.yaml:38 scenarios/mysql/02-isolation/circular-information-flow.yaml#steps[11].B B ROLLBACK M15 MySQL 8.4.11, InnoDB; before step: A=READ UNCOMMITTED, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=READ UNCOMMITTED, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Replaced at the corresponding logical occurrence; current occurrence scenarios/mysql/02-isolation/circular-information-flow.yaml#steps[11].B at scenarios/mysql/02-isolation/circular-information-flow.yaml:40 C00376 base scenarios/mysql/02-isolation/circular-information-flow.yaml:39 scenarios/mysql/02-isolation/circular-information-flow.yaml#steps[11].tl tl ROLLBACK M15 MySQL 8.4.11, InnoDB; before step: A=READ UNCOMMITTED, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=READ UNCOMMITTED, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Replaced at the corresponding logical occurrence; current occurrence scenarios/mysql/02-isolation/circular-information-flow.yaml#steps[11].tl at scenarios/mysql/02-isolation/circular-information-flow.yaml:41 C00377 base scenarios/mysql/02-isolation/circular-information-flow.yaml:41 scenarios/mysql/02-isolation/circular-information-flow.yaml#steps[12].note note The same dance at READ COMMITTED: each sees the world before the other. M15 MySQL 8.4.11, InnoDB; before step: A=READ UNCOMMITTED, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ UNCOMMITTED, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Replaced at the corresponding logical occurrence; current occurrence scenarios/mysql/02-isolation/circular-information-flow.yaml#steps[14].note at scenarios/mysql/02-isolation/circular-information-flow.yaml:46 C00378 base scenarios/mysql/02-isolation/circular-information-flow.yaml:42 scenarios/mysql/02-isolation/circular-information-flow.yaml#steps[13].A A SET SESSION TRANSACTION ISOLATION LEVEL READ COMMITTED M15 MySQL 8.4.11, InnoDB; before step: A=READ UNCOMMITTED, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/circular-information-flow.yaml#steps[15].A at scenarios/mysql/02-isolation/circular-information-flow.yaml:47 C00379 base scenarios/mysql/02-isolation/circular-information-flow.yaml:43 scenarios/mysql/02-isolation/circular-information-flow.yaml#steps[14].B B SET SESSION TRANSACTION ISOLATION LEVEL READ COMMITTED M15 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, standalone/next transaction, autocommit=1; B=READ COMMITTED, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/circular-information-flow.yaml#steps[16].B at scenarios/mysql/02-isolation/circular-information-flow.yaml:48 C00380 base scenarios/mysql/02-isolation/circular-information-flow.yaml:44 scenarios/mysql/02-isolation/circular-information-flow.yaml#steps[15].A A BEGIN M15 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, standalone/next transaction, autocommit=1; B=READ COMMITTED, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, open transaction, autocommit=1; B=READ COMMITTED, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/circular-information-flow.yaml#steps[17].A at scenarios/mysql/02-isolation/circular-information-flow.yaml:49 C00381 base scenarios/mysql/02-isolation/circular-information-flow.yaml:45 scenarios/mysql/02-isolation/circular-information-flow.yaml#steps[16].B B BEGIN M15 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, open transaction, autocommit=1; B=READ COMMITTED, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, open transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/circular-information-flow.yaml#steps[18].B at scenarios/mysql/02-isolation/circular-information-flow.yaml:50 C00382 base scenarios/mysql/02-isolation/circular-information-flow.yaml:46 scenarios/mysql/02-isolation/circular-information-flow.yaml#steps[17].A A UPDATE accounts SET balance = 111 WHERE id = 1 M15 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, open transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, open transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/circular-information-flow.yaml#steps[19].A at scenarios/mysql/02-isolation/circular-information-flow.yaml:51 C00383 base scenarios/mysql/02-isolation/circular-information-flow.yaml:47 scenarios/mysql/02-isolation/circular-information-flow.yaml#steps[18].B B UPDATE accounts SET balance = 222 WHERE id = 2 M15 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, open transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, open transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/circular-information-flow.yaml#steps[20].B at scenarios/mysql/02-isolation/circular-information-flow.yaml:52 C00384 base scenarios/mysql/02-isolation/circular-information-flow.yaml:48 scenarios/mysql/02-isolation/circular-information-flow.yaml#steps[19].A A SELECT balance FROM accounts WHERE id = 2 M15 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, open transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, open transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/circular-information-flow.yaml#steps[21].A at scenarios/mysql/02-isolation/circular-information-flow.yaml:53 C00385 base scenarios/mysql/02-isolation/circular-information-flow.yaml:49 scenarios/mysql/02-isolation/circular-information-flow.yaml#steps[19].expect[0].balance balance 100 M15 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, open transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, open transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/circular-information-flow.yaml#steps[21].expect[0].balance at scenarios/mysql/02-isolation/circular-information-flow.yaml:54 C00386 base scenarios/mysql/02-isolation/circular-information-flow.yaml:50 scenarios/mysql/02-isolation/circular-information-flow.yaml#steps[20].B B SELECT balance FROM accounts WHERE id = 1 M15 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, open transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, open transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/circular-information-flow.yaml#steps[22].B at scenarios/mysql/02-isolation/circular-information-flow.yaml:55 C00387 base scenarios/mysql/02-isolation/circular-information-flow.yaml:51 scenarios/mysql/02-isolation/circular-information-flow.yaml#steps[20].expect[0].balance balance 100 M15 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, open transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, open transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/circular-information-flow.yaml#steps[22].expect[0].balance at scenarios/mysql/02-isolation/circular-information-flow.yaml:56 C00388 base scenarios/mysql/02-isolation/circular-information-flow.yaml:52 scenarios/mysql/02-isolation/circular-information-flow.yaml#steps[21].A A COMMIT M15 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, open transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, standalone/next transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/circular-information-flow.yaml#steps[23].A at scenarios/mysql/02-isolation/circular-information-flow.yaml:57 C00389 base scenarios/mysql/02-isolation/circular-information-flow.yaml:53 scenarios/mysql/02-isolation/circular-information-flow.yaml#steps[22].B B COMMIT M15 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, standalone/next transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, standalone/next transaction, autocommit=1; B=READ COMMITTED, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/circular-information-flow.yaml#steps[24].B at scenarios/mysql/02-isolation/circular-information-flow.yaml:58 C00390 base scenarios/mysql/02-isolation/current-reads.yaml:1 scenarios/mysql/02-isolation/current-reads.yaml#title title Current reads punch holes in the snapshot M16 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/02-isolation/current-reads.yaml#title at scenarios/mysql/02-isolation/current-reads.yaml:1 C00391 base scenarios/mysql/02-isolation/current-reads.yaml:2 scenarios/mysql/02-isolation/current-reads.yaml#claim claim A REPEATABLE READ transaction's UPDATE operates on the CURRENT committed row, not on its snapshot — and afterwards the transaction sees its own write, so the 'repeatable' read changes. M16 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Replaced at the corresponding logical occurrence; current occurrence scenarios/mysql/02-isolation/current-reads.yaml#claim at scenarios/mysql/02-isolation/current-reads.yaml:2 C00392 base scenarios/mysql/02-isolation/current-reads.yaml:6 scenarios/mysql/02-isolation/current-reads.yaml#setup setup "CREATE TABLE accounts (id int PRIMARY KEY, owner varchar(20) NOT NULL, balance int NOT NULL); INSERT INTO accounts VALUES (1, 'alice', 100); " M16 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Replaced at the corresponding logical occurrence; current occurrence scenarios/mysql/02-isolation/current-reads.yaml#setup at scenarios/mysql/02-isolation/current-reads.yaml:6 C00393 base scenarios/mysql/02-isolation/current-reads.yaml:9 scenarios/mysql/02-isolation/current-reads.yaml#sessions[0] sessions[0] A M16 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/current-reads.yaml#sessions[0] at scenarios/mysql/02-isolation/current-reads.yaml:9 C00394 base scenarios/mysql/02-isolation/current-reads.yaml:9 scenarios/mysql/02-isolation/current-reads.yaml#sessions[1] sessions[1] B M16 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/current-reads.yaml#sessions[1] at scenarios/mysql/02-isolation/current-reads.yaml:9 C00395 base scenarios/mysql/02-isolation/current-reads.yaml:11 scenarios/mysql/02-isolation/current-reads.yaml#steps[0].A A BEGIN M16 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/current-reads.yaml#steps[1].A at scenarios/mysql/02-isolation/current-reads.yaml:12 C00396 base scenarios/mysql/02-isolation/current-reads.yaml:12 scenarios/mysql/02-isolation/current-reads.yaml#steps[1].A A SELECT balance FROM accounts WHERE id = 1 M16 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/current-reads.yaml#steps[2].A at scenarios/mysql/02-isolation/current-reads.yaml:13 C00397 base scenarios/mysql/02-isolation/current-reads.yaml:13 scenarios/mysql/02-isolation/current-reads.yaml#steps[1].expect[0].balance balance 100 M16 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/current-reads.yaml#steps[2].expect[0].balance at scenarios/mysql/02-isolation/current-reads.yaml:14 C00398 base scenarios/mysql/02-isolation/current-reads.yaml:14 scenarios/mysql/02-isolation/current-reads.yaml#steps[1].comment comment snapshot taken M16 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/02-isolation/current-reads.yaml#steps[2].comment at scenarios/mysql/02-isolation/current-reads.yaml:15 C00399 base scenarios/mysql/02-isolation/current-reads.yaml:15 scenarios/mysql/02-isolation/current-reads.yaml#steps[1].tl tl SELECT balance → 100 (snapshot) M16 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/02-isolation/current-reads.yaml#steps[2].tl at scenarios/mysql/02-isolation/current-reads.yaml:16 C00400 base scenarios/mysql/02-isolation/current-reads.yaml:17 scenarios/mysql/02-isolation/current-reads.yaml#steps[2].note note B commits a change. A keeps READING its stale snapshot… M16 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/02-isolation/current-reads.yaml#steps[3].note at scenarios/mysql/02-isolation/current-reads.yaml:18 C00401 base scenarios/mysql/02-isolation/current-reads.yaml:18 scenarios/mysql/02-isolation/current-reads.yaml#steps[3].B B UPDATE accounts SET balance = 150 WHERE id = 1 M16 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/current-reads.yaml#steps[4].B at scenarios/mysql/02-isolation/current-reads.yaml:19 C00402 base scenarios/mysql/02-isolation/current-reads.yaml:19 scenarios/mysql/02-isolation/current-reads.yaml#steps[3].tl tl UPDATE balance = 150 (committed) M16 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/02-isolation/current-reads.yaml#steps[4].tl at scenarios/mysql/02-isolation/current-reads.yaml:20 C00403 base scenarios/mysql/02-isolation/current-reads.yaml:21 scenarios/mysql/02-isolation/current-reads.yaml#steps[4].A A SELECT balance FROM accounts WHERE id = 1 M16 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/current-reads.yaml#steps[5].A at scenarios/mysql/02-isolation/current-reads.yaml:22 C00404 base scenarios/mysql/02-isolation/current-reads.yaml:22 scenarios/mysql/02-isolation/current-reads.yaml#steps[4].expect[0].balance balance 100 M16 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/current-reads.yaml#steps[5].expect[0].balance at scenarios/mysql/02-isolation/current-reads.yaml:23 C00405 base scenarios/mysql/02-isolation/current-reads.yaml:23 scenarios/mysql/02-isolation/current-reads.yaml#steps[4].tl tl SELECT balance → 100 (snapshot holds) M16 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/02-isolation/current-reads.yaml#steps[5].tl at scenarios/mysql/02-isolation/current-reads.yaml:24 C00406 base scenarios/mysql/02-isolation/current-reads.yaml:25 scenarios/mysql/02-isolation/current-reads.yaml#steps[5].note note …but A's UPDATE is a current read: it computes from B's committed 150, not from the snapshot's 100. M16 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/02-isolation/current-reads.yaml#steps[6].note at scenarios/mysql/02-isolation/current-reads.yaml:26 C00407 base scenarios/mysql/02-isolation/current-reads.yaml:28 scenarios/mysql/02-isolation/current-reads.yaml#steps[6].A A UPDATE accounts SET balance = balance + 50 WHERE id = 1 M16 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/current-reads.yaml#steps[7].A at scenarios/mysql/02-isolation/current-reads.yaml:29 C00408 base scenarios/mysql/02-isolation/current-reads.yaml:29 scenarios/mysql/02-isolation/current-reads.yaml#steps[6].tl tl UPDATE +50 (current read of 150) M16 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/02-isolation/current-reads.yaml#steps[7].tl at scenarios/mysql/02-isolation/current-reads.yaml:30 C00409 base scenarios/mysql/02-isolation/current-reads.yaml:31 scenarios/mysql/02-isolation/current-reads.yaml#steps[7].A A SELECT balance FROM accounts WHERE id = 1 M16 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/current-reads.yaml#steps[8].A at scenarios/mysql/02-isolation/current-reads.yaml:32 C00410 base scenarios/mysql/02-isolation/current-reads.yaml:32 scenarios/mysql/02-isolation/current-reads.yaml#steps[7].expect[0].balance balance 200 M16 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/current-reads.yaml#steps[8].expect[0].balance at scenarios/mysql/02-isolation/current-reads.yaml:33 C00411 base scenarios/mysql/02-isolation/current-reads.yaml:33 scenarios/mysql/02-isolation/current-reads.yaml#steps[7].comment comment 150 + 50 — and now A sees it: the snapshot has a hole M16 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Replaced at the corresponding logical occurrence; current occurrence scenarios/mysql/02-isolation/current-reads.yaml#steps[8].comment at scenarios/mysql/02-isolation/current-reads.yaml:34 C00412 base scenarios/mysql/02-isolation/current-reads.yaml:34 scenarios/mysql/02-isolation/current-reads.yaml#steps[7].tl tl SELECT balance → 200 (150 + 50 — the hole) M16 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Replaced at the corresponding logical occurrence; current occurrence scenarios/mysql/02-isolation/current-reads.yaml#steps[8].tl at scenarios/mysql/02-isolation/current-reads.yaml:35 C00413 base scenarios/mysql/02-isolation/current-reads.yaml:36 scenarios/mysql/02-isolation/current-reads.yaml#steps[8].A A COMMIT M16 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/current-reads.yaml#steps[9].A at scenarios/mysql/02-isolation/current-reads.yaml:37 C00414 base scenarios/mysql/02-isolation/current-reads.yaml:37 scenarios/mysql/02-isolation/current-reads.yaml#steps[8].tl tl COMMIT M16 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/02-isolation/current-reads.yaml#steps[9].tl at scenarios/mysql/02-isolation/current-reads.yaml:38 C00415 base scenarios/mysql/02-isolation/current-reads.yaml:38 scenarios/mysql/02-isolation/current-reads.yaml#steps[9].note note PostgreSQL would have aborted A's UPDATE with 40001 instead. MySQL quietly switches world views. M16 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Replaced at the corresponding logical occurrence; current occurrence scenarios/mysql/02-isolation/current-reads.yaml#steps[10].note at scenarios/mysql/02-isolation/current-reads.yaml:39 C00416 base scenarios/mysql/02-isolation/current-reads.yaml:40 scenarios/mysql/02-isolation/current-reads.yaml#steps[10].note note If the competing write is NOT yet committed, A first waits on the row lock… M16 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/02-isolation/current-reads.yaml#steps[11].note at scenarios/mysql/02-isolation/current-reads.yaml:41 C00417 base scenarios/mysql/02-isolation/current-reads.yaml:41 scenarios/mysql/02-isolation/current-reads.yaml#steps[11].A A BEGIN M16 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/current-reads.yaml#steps[12].A at scenarios/mysql/02-isolation/current-reads.yaml:42 C00418 base scenarios/mysql/02-isolation/current-reads.yaml:42 scenarios/mysql/02-isolation/current-reads.yaml#steps[12].A A SELECT balance FROM accounts WHERE id = 1 M16 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/current-reads.yaml#steps[13].A at scenarios/mysql/02-isolation/current-reads.yaml:43 C00419 base scenarios/mysql/02-isolation/current-reads.yaml:43 scenarios/mysql/02-isolation/current-reads.yaml#steps[12].comment comment snapshot taken M16 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/02-isolation/current-reads.yaml#steps[13].comment at scenarios/mysql/02-isolation/current-reads.yaml:45 C00420 base scenarios/mysql/02-isolation/current-reads.yaml:45 scenarios/mysql/02-isolation/current-reads.yaml#steps[13].B B BEGIN M16 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/current-reads.yaml#steps[14].B at scenarios/mysql/02-isolation/current-reads.yaml:47 C00421 base scenarios/mysql/02-isolation/current-reads.yaml:46 scenarios/mysql/02-isolation/current-reads.yaml#steps[14].B B UPDATE accounts SET balance = 300 WHERE id = 1 M16 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/current-reads.yaml#steps[15].B at scenarios/mysql/02-isolation/current-reads.yaml:48 C00422 base scenarios/mysql/02-isolation/current-reads.yaml:48 scenarios/mysql/02-isolation/current-reads.yaml#steps[15].A A UPDATE accounts SET balance = balance + 50 WHERE id = 1 M16 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/current-reads.yaml#steps[16].A at scenarios/mysql/02-isolation/current-reads.yaml:50 C00423 base scenarios/mysql/02-isolation/current-reads.yaml:49 scenarios/mysql/02-isolation/current-reads.yaml#steps[15].blocks blocks p1 M16 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/current-reads.yaml#steps[16].blocks at scenarios/mysql/02-isolation/current-reads.yaml:51 C00424 base scenarios/mysql/02-isolation/current-reads.yaml:51 scenarios/mysql/02-isolation/current-reads.yaml#steps[16].note note …and proceeds from B's value the moment B commits. No error here either. M16 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/02-isolation/current-reads.yaml#steps[17].note at scenarios/mysql/02-isolation/current-reads.yaml:53 C00425 base scenarios/mysql/02-isolation/current-reads.yaml:52 scenarios/mysql/02-isolation/current-reads.yaml#steps[17].B B COMMIT M16 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/current-reads.yaml#steps[18].B at scenarios/mysql/02-isolation/current-reads.yaml:54 C00426 base scenarios/mysql/02-isolation/current-reads.yaml:54 scenarios/mysql/02-isolation/current-reads.yaml#steps[18].success success p1 M16 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/current-reads.yaml#steps[19].success at scenarios/mysql/02-isolation/current-reads.yaml:56 C00427 base scenarios/mysql/02-isolation/current-reads.yaml:55 scenarios/mysql/02-isolation/current-reads.yaml#steps[19].A A SELECT balance FROM accounts WHERE id = 1 M16 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/current-reads.yaml#steps[20].A at scenarios/mysql/02-isolation/current-reads.yaml:57 C00428 base scenarios/mysql/02-isolation/current-reads.yaml:56 scenarios/mysql/02-isolation/current-reads.yaml#steps[19].expect[0].balance balance 350 M16 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/current-reads.yaml#steps[20].expect[0].balance at scenarios/mysql/02-isolation/current-reads.yaml:58 C00429 base scenarios/mysql/02-isolation/current-reads.yaml:57 scenarios/mysql/02-isolation/current-reads.yaml#steps[19].comment comment 300 + 50 M16 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/02-isolation/current-reads.yaml#steps[20].comment at scenarios/mysql/02-isolation/current-reads.yaml:59 C00430 base scenarios/mysql/02-isolation/current-reads.yaml:58 scenarios/mysql/02-isolation/current-reads.yaml#steps[20].A A COMMIT M16 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/current-reads.yaml#steps[21].A at scenarios/mysql/02-isolation/current-reads.yaml:60 C00431 base scenarios/mysql/02-isolation/dirty-read.yaml:1 scenarios/mysql/02-isolation/dirty-read.yaml#title title READ UNCOMMITTED really reads uncommitted data M17 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/02-isolation/dirty-read.yaml#title at scenarios/mysql/02-isolation/dirty-read.yaml:1 C00432 base scenarios/mysql/02-isolation/dirty-read.yaml:2 scenarios/mysql/02-isolation/dirty-read.yaml#claim claim At READ UNCOMMITTED, MySQL serves other transactions' uncommitted changes — including values that are later rolled back and thus never existed. M17 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Replaced at the corresponding logical occurrence; current occurrence scenarios/mysql/02-isolation/dirty-read.yaml#claim at scenarios/mysql/02-isolation/dirty-read.yaml:2 C00433 base scenarios/mysql/02-isolation/dirty-read.yaml:5 scenarios/mysql/02-isolation/dirty-read.yaml#anomaly anomaly G1a M17 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/dirty-read.yaml#anomaly at scenarios/mysql/02-isolation/dirty-read.yaml:6 C00434 base scenarios/mysql/02-isolation/dirty-read.yaml:6 scenarios/mysql/02-isolation/dirty-read.yaml#isolation isolation READ UNCOMMITTED M17 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/dirty-read.yaml#isolation at scenarios/mysql/02-isolation/dirty-read.yaml:7 C00435 base scenarios/mysql/02-isolation/dirty-read.yaml:7 scenarios/mysql/02-isolation/dirty-read.yaml#setup setup "CREATE TABLE accounts (id int PRIMARY KEY, owner varchar(20) NOT NULL, balance int NOT NULL); INSERT INTO accounts VALUES (1, 'alice', 100); " M17 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Replaced at the corresponding logical occurrence; current occurrence scenarios/mysql/02-isolation/dirty-read.yaml#setup at scenarios/mysql/02-isolation/dirty-read.yaml:8 C00436 base scenarios/mysql/02-isolation/dirty-read.yaml:10 scenarios/mysql/02-isolation/dirty-read.yaml#sessions[0] sessions[0] A M17 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/dirty-read.yaml#sessions[0] at scenarios/mysql/02-isolation/dirty-read.yaml:11 C00437 base scenarios/mysql/02-isolation/dirty-read.yaml:10 scenarios/mysql/02-isolation/dirty-read.yaml#sessions[1] sessions[1] B M17 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/dirty-read.yaml#sessions[1] at scenarios/mysql/02-isolation/dirty-read.yaml:11 C00438 base scenarios/mysql/02-isolation/dirty-read.yaml:12 scenarios/mysql/02-isolation/dirty-read.yaml#steps[0].A A BEGIN M17 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/dirty-read.yaml#steps[0].A at scenarios/mysql/02-isolation/dirty-read.yaml:13 C00439 base scenarios/mysql/02-isolation/dirty-read.yaml:13 scenarios/mysql/02-isolation/dirty-read.yaml#steps[1].A A UPDATE accounts SET balance = 999 WHERE id = 1 M17 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/dirty-read.yaml#steps[1].A at scenarios/mysql/02-isolation/dirty-read.yaml:14 C00440 base scenarios/mysql/02-isolation/dirty-read.yaml:14 scenarios/mysql/02-isolation/dirty-read.yaml#steps[1].tl tl UPDATE balance = 999 (uncommitted) M17 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/02-isolation/dirty-read.yaml#steps[1].tl at scenarios/mysql/02-isolation/dirty-read.yaml:15 C00441 base scenarios/mysql/02-isolation/dirty-read.yaml:16 scenarios/mysql/02-isolation/dirty-read.yaml#steps[2].note note B opts into READ UNCOMMITTED — and sees A's uncommitted 999. M17 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Replaced at the corresponding logical occurrence; current occurrence scenarios/mysql/02-isolation/dirty-read.yaml#steps[2].note at scenarios/mysql/02-isolation/dirty-read.yaml:17 C00442 base scenarios/mysql/02-isolation/dirty-read.yaml:17 scenarios/mysql/02-isolation/dirty-read.yaml#steps[3].B B SET SESSION TRANSACTION ISOLATION LEVEL READ UNCOMMITTED M17 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=READ UNCOMMITTED, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/dirty-read.yaml#steps[3].B at scenarios/mysql/02-isolation/dirty-read.yaml:18 C00443 base scenarios/mysql/02-isolation/dirty-read.yaml:18 scenarios/mysql/02-isolation/dirty-read.yaml#steps[4].B B BEGIN M17 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=READ UNCOMMITTED, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/dirty-read.yaml#steps[4].B at scenarios/mysql/02-isolation/dirty-read.yaml:19 C00444 base scenarios/mysql/02-isolation/dirty-read.yaml:20 scenarios/mysql/02-isolation/dirty-read.yaml#steps[5].B B SELECT @@transaction_isolation AS isolation M17 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/dirty-read.yaml#steps[5].B at scenarios/mysql/02-isolation/dirty-read.yaml:21 C00445 base scenarios/mysql/02-isolation/dirty-read.yaml:21 scenarios/mysql/02-isolation/dirty-read.yaml#steps[5].expect[0].isolation isolation READ-UNCOMMITTED M17 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/dirty-read.yaml#steps[5].expect[0].isolation at scenarios/mysql/02-isolation/dirty-read.yaml:22 C00446 base scenarios/mysql/02-isolation/dirty-read.yaml:23 scenarios/mysql/02-isolation/dirty-read.yaml#steps[6].B B SELECT balance FROM accounts WHERE id = 1 M17 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/dirty-read.yaml#steps[6].B at scenarios/mysql/02-isolation/dirty-read.yaml:24 C00447 base scenarios/mysql/02-isolation/dirty-read.yaml:24 scenarios/mysql/02-isolation/dirty-read.yaml#steps[6].expect[0].balance balance 999 M17 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/dirty-read.yaml#steps[6].expect[0].balance at scenarios/mysql/02-isolation/dirty-read.yaml:25 C00448 base scenarios/mysql/02-isolation/dirty-read.yaml:25 scenarios/mysql/02-isolation/dirty-read.yaml#steps[6].comment comment a dirty read — A never committed this M17 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Replaced at the corresponding logical occurrence; current occurrence scenarios/mysql/02-isolation/dirty-read.yaml#steps[6].comment at scenarios/mysql/02-isolation/dirty-read.yaml:26 C00449 base scenarios/mysql/02-isolation/dirty-read.yaml:26 scenarios/mysql/02-isolation/dirty-read.yaml#steps[6].tl tl SELECT balance → 999 (dirty read) M17 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/02-isolation/dirty-read.yaml#steps[6].tl at scenarios/mysql/02-isolation/dirty-read.yaml:27 C00450 base scenarios/mysql/02-isolation/dirty-read.yaml:28 scenarios/mysql/02-isolation/dirty-read.yaml#steps[7].note note A rolls back. The 999 B just read never existed. M17 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Replaced at the corresponding logical occurrence; current occurrence scenarios/mysql/02-isolation/dirty-read.yaml#steps[7].note at scenarios/mysql/02-isolation/dirty-read.yaml:29 C00451 base scenarios/mysql/02-isolation/dirty-read.yaml:29 scenarios/mysql/02-isolation/dirty-read.yaml#steps[8].A A ROLLBACK M17 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/dirty-read.yaml#steps[8].A at scenarios/mysql/02-isolation/dirty-read.yaml:30 C00452 base scenarios/mysql/02-isolation/dirty-read.yaml:30 scenarios/mysql/02-isolation/dirty-read.yaml#steps[8].tl tl ROLLBACK — 999 never existed M17 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Replaced at the corresponding logical occurrence; current occurrence scenarios/mysql/02-isolation/dirty-read.yaml#steps[8].tl at scenarios/mysql/02-isolation/dirty-read.yaml:31 C00453 base scenarios/mysql/02-isolation/dirty-read.yaml:32 scenarios/mysql/02-isolation/dirty-read.yaml#steps[9].B B SELECT balance FROM accounts WHERE id = 1 M17 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/dirty-read.yaml#steps[9].B at scenarios/mysql/02-isolation/dirty-read.yaml:33 C00454 base scenarios/mysql/02-isolation/dirty-read.yaml:33 scenarios/mysql/02-isolation/dirty-read.yaml#steps[9].expect[0].balance balance 100 M17 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/dirty-read.yaml#steps[9].expect[0].balance at scenarios/mysql/02-isolation/dirty-read.yaml:34 C00455 base scenarios/mysql/02-isolation/dirty-read.yaml:34 scenarios/mysql/02-isolation/dirty-read.yaml#steps[9].tl tl SELECT balance → 100 (the real value) M17 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/02-isolation/dirty-read.yaml#steps[9].tl at scenarios/mysql/02-isolation/dirty-read.yaml:35 C00456 base scenarios/mysql/02-isolation/dirty-read.yaml:35 scenarios/mysql/02-isolation/dirty-read.yaml#steps[10].B B COMMIT M17 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/dirty-read.yaml#steps[10].B at scenarios/mysql/02-isolation/dirty-read.yaml:36 C00457 base scenarios/mysql/02-isolation/dirty-write.yaml:1 scenarios/mysql/02-isolation/dirty-write.yaml#title title Dirty writes are impossible — even at READ UNCOMMITTED M18 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Replaced at the corresponding logical occurrence; current occurrence scenarios/mysql/02-isolation/dirty-write.yaml#title at scenarios/mysql/02-isolation/dirty-write.yaml:1 C00458 base scenarios/mysql/02-isolation/dirty-write.yaml:2 scenarios/mysql/02-isolation/dirty-write.yaml#claim claim "InnoDB always takes exclusive row locks for writes, so two transactions repricing the same rows cannot interleave their writes (Adya's G0, ""dirty write"") at any isolation level — even the one that allows dirty reads." M18 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Replaced at the corresponding logical occurrence; current occurrence scenarios/mysql/02-isolation/dirty-write.yaml#claim at scenarios/mysql/02-isolation/dirty-write.yaml:2 C00459 base scenarios/mysql/02-isolation/dirty-write.yaml:6 scenarios/mysql/02-isolation/dirty-write.yaml#anomaly anomaly G0 M18 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/dirty-write.yaml#anomaly at scenarios/mysql/02-isolation/dirty-write.yaml:6 C00460 base scenarios/mysql/02-isolation/dirty-write.yaml:7 scenarios/mysql/02-isolation/dirty-write.yaml#isolation isolation READ UNCOMMITTED M18 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/dirty-write.yaml#isolation at scenarios/mysql/02-isolation/dirty-write.yaml:7 C00461 base scenarios/mysql/02-isolation/dirty-write.yaml:8 scenarios/mysql/02-isolation/dirty-write.yaml#setup setup "CREATE TABLE items (id int PRIMARY KEY, name varchar(20) NOT NULL, price int NOT NULL); INSERT INTO items VALUES (1, 'mug', 10), (2, 'cap', 20); " M18 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Replaced at the corresponding logical occurrence; current occurrence scenarios/mysql/02-isolation/dirty-write.yaml#setup at scenarios/mysql/02-isolation/dirty-write.yaml:8 C00462 base scenarios/mysql/02-isolation/dirty-write.yaml:11 scenarios/mysql/02-isolation/dirty-write.yaml#sessions[0] sessions[0] A M18 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/dirty-write.yaml#sessions[0] at scenarios/mysql/02-isolation/dirty-write.yaml:11 C00463 base scenarios/mysql/02-isolation/dirty-write.yaml:11 scenarios/mysql/02-isolation/dirty-write.yaml#sessions[1] sessions[1] B M18 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/dirty-write.yaml#sessions[1] at scenarios/mysql/02-isolation/dirty-write.yaml:11 C00464 base scenarios/mysql/02-isolation/dirty-write.yaml:13 scenarios/mysql/02-isolation/dirty-write.yaml#steps[0].note note Two batch jobs reprice the whole catalog concurrently — at READ UNCOMMITTED, the weakest level MySQL has. A mix of their prices (A's mug with B's cap) would be a dirty write: a state no serial order could produce. M18 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Replaced at the corresponding logical occurrence; current occurrence scenarios/mysql/02-isolation/dirty-write.yaml#steps[0].note at scenarios/mysql/02-isolation/dirty-write.yaml:13 C00465 base scenarios/mysql/02-isolation/dirty-write.yaml:17 scenarios/mysql/02-isolation/dirty-write.yaml#steps[1].A A SET SESSION TRANSACTION ISOLATION LEVEL READ UNCOMMITTED M18 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ UNCOMMITTED, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/dirty-write.yaml#steps[1].A at scenarios/mysql/02-isolation/dirty-write.yaml:17 C00466 base scenarios/mysql/02-isolation/dirty-write.yaml:18 scenarios/mysql/02-isolation/dirty-write.yaml#steps[2].B B SET SESSION TRANSACTION ISOLATION LEVEL READ UNCOMMITTED M18 MySQL 8.4.11, InnoDB; before step: A=READ UNCOMMITTED, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ UNCOMMITTED, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/dirty-write.yaml#steps[2].B at scenarios/mysql/02-isolation/dirty-write.yaml:18 C00467 base scenarios/mysql/02-isolation/dirty-write.yaml:19 scenarios/mysql/02-isolation/dirty-write.yaml#steps[3].A A BEGIN M18 MySQL 8.4.11, InnoDB; before step: A=READ UNCOMMITTED, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ UNCOMMITTED, open transaction, autocommit=1; B=READ UNCOMMITTED, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/dirty-write.yaml#steps[3].A at scenarios/mysql/02-isolation/dirty-write.yaml:19 C00468 base scenarios/mysql/02-isolation/dirty-write.yaml:20 scenarios/mysql/02-isolation/dirty-write.yaml#steps[4].B B BEGIN M18 MySQL 8.4.11, InnoDB; before step: A=READ UNCOMMITTED, open transaction, autocommit=1; B=READ UNCOMMITTED, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ UNCOMMITTED, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/dirty-write.yaml#steps[4].B at scenarios/mysql/02-isolation/dirty-write.yaml:20 C00469 base scenarios/mysql/02-isolation/dirty-write.yaml:21 scenarios/mysql/02-isolation/dirty-write.yaml#steps[5].A A UPDATE items SET price = 11 WHERE id = 1 M18 MySQL 8.4.11, InnoDB; before step: A=READ UNCOMMITTED, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=READ UNCOMMITTED, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/dirty-write.yaml#steps[5].A at scenarios/mysql/02-isolation/dirty-write.yaml:21 C00470 base scenarios/mysql/02-isolation/dirty-write.yaml:22 scenarios/mysql/02-isolation/dirty-write.yaml#steps[5].tl tl UPDATE mug = 11 M18 MySQL 8.4.11, InnoDB; before step: A=READ UNCOMMITTED, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=READ UNCOMMITTED, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/02-isolation/dirty-write.yaml#steps[5].tl at scenarios/mysql/02-isolation/dirty-write.yaml:22 C00471 base scenarios/mysql/02-isolation/dirty-write.yaml:24 scenarios/mysql/02-isolation/dirty-write.yaml#steps[6].note note B may READ A's uncommitted rows at this level — but it may not overwrite them. M18 MySQL 8.4.11, InnoDB; before step: A=READ UNCOMMITTED, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=READ UNCOMMITTED, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Replaced at the corresponding logical occurrence; current occurrence scenarios/mysql/02-isolation/dirty-write.yaml#steps[6].note at scenarios/mysql/02-isolation/dirty-write.yaml:24 C00472 base scenarios/mysql/02-isolation/dirty-write.yaml:25 scenarios/mysql/02-isolation/dirty-write.yaml#steps[7].B B UPDATE items SET price = 12 WHERE id = 1 M18 MySQL 8.4.11, InnoDB; before step: A=READ UNCOMMITTED, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=READ UNCOMMITTED, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/dirty-write.yaml#steps[7].B at scenarios/mysql/02-isolation/dirty-write.yaml:25 C00473 base scenarios/mysql/02-isolation/dirty-write.yaml:26 scenarios/mysql/02-isolation/dirty-write.yaml#steps[7].blocks blocks p1 M18 MySQL 8.4.11, InnoDB; before step: A=READ UNCOMMITTED, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=READ UNCOMMITTED, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/dirty-write.yaml#steps[7].blocks at scenarios/mysql/02-isolation/dirty-write.yaml:26 C00474 base scenarios/mysql/02-isolation/dirty-write.yaml:27 scenarios/mysql/02-isolation/dirty-write.yaml#steps[7].tl tl UPDATE mug = 12 M18 MySQL 8.4.11, InnoDB; before step: A=READ UNCOMMITTED, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=READ UNCOMMITTED, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/02-isolation/dirty-write.yaml#steps[7].tl at scenarios/mysql/02-isolation/dirty-write.yaml:27 C00475 base scenarios/mysql/02-isolation/dirty-write.yaml:29 scenarios/mysql/02-isolation/dirty-write.yaml#steps[8].A A UPDATE items SET price = 21 WHERE id = 2 M18 MySQL 8.4.11, InnoDB; before step: A=READ UNCOMMITTED, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=READ UNCOMMITTED, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/dirty-write.yaml#steps[8].A at scenarios/mysql/02-isolation/dirty-write.yaml:29 C00476 base scenarios/mysql/02-isolation/dirty-write.yaml:30 scenarios/mysql/02-isolation/dirty-write.yaml#steps[8].tl tl UPDATE cap = 21 M18 MySQL 8.4.11, InnoDB; before step: A=READ UNCOMMITTED, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=READ UNCOMMITTED, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/02-isolation/dirty-write.yaml#steps[8].tl at scenarios/mysql/02-isolation/dirty-write.yaml:30 C00477 base scenarios/mysql/02-isolation/dirty-write.yaml:31 scenarios/mysql/02-isolation/dirty-write.yaml#steps[9].A A COMMIT M18 MySQL 8.4.11, InnoDB; before step: A=READ UNCOMMITTED, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=READ UNCOMMITTED, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/dirty-write.yaml#steps[9].A at scenarios/mysql/02-isolation/dirty-write.yaml:31 C00478 base scenarios/mysql/02-isolation/dirty-write.yaml:32 scenarios/mysql/02-isolation/dirty-write.yaml#steps[9].comment comment releases both row locks M18 MySQL 8.4.11, InnoDB; before step: A=READ UNCOMMITTED, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=READ UNCOMMITTED, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/02-isolation/dirty-write.yaml#steps[9].comment at scenarios/mysql/02-isolation/dirty-write.yaml:32 C00479 base scenarios/mysql/02-isolation/dirty-write.yaml:33 scenarios/mysql/02-isolation/dirty-write.yaml#steps[9].tl tl COMMIT M18 MySQL 8.4.11, InnoDB; before step: A=READ UNCOMMITTED, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=READ UNCOMMITTED, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/02-isolation/dirty-write.yaml#steps[9].tl at scenarios/mysql/02-isolation/dirty-write.yaml:33 C00480 base scenarios/mysql/02-isolation/dirty-write.yaml:34 scenarios/mysql/02-isolation/dirty-write.yaml#steps[10].success success p1 M18 MySQL 8.4.11, InnoDB; before step: A=READ UNCOMMITTED, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=READ UNCOMMITTED, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/dirty-write.yaml#steps[10].success at scenarios/mysql/02-isolation/dirty-write.yaml:34 C00481 base scenarios/mysql/02-isolation/dirty-write.yaml:36 scenarios/mysql/02-isolation/dirty-write.yaml#steps[11].B B UPDATE items SET price = 22 WHERE id = 2 M18 MySQL 8.4.11, InnoDB; before step: A=READ UNCOMMITTED, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=READ UNCOMMITTED, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/dirty-write.yaml#steps[11].B at scenarios/mysql/02-isolation/dirty-write.yaml:36 C00482 base scenarios/mysql/02-isolation/dirty-write.yaml:37 scenarios/mysql/02-isolation/dirty-write.yaml#steps[11].tl tl UPDATE cap = 22 M18 MySQL 8.4.11, InnoDB; before step: A=READ UNCOMMITTED, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=READ UNCOMMITTED, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/02-isolation/dirty-write.yaml#steps[11].tl at scenarios/mysql/02-isolation/dirty-write.yaml:37 C00483 base scenarios/mysql/02-isolation/dirty-write.yaml:38 scenarios/mysql/02-isolation/dirty-write.yaml#steps[12].B B COMMIT M18 MySQL 8.4.11, InnoDB; before step: A=READ UNCOMMITTED, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=READ UNCOMMITTED, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/dirty-write.yaml#steps[12].B at scenarios/mysql/02-isolation/dirty-write.yaml:38 C00484 base scenarios/mysql/02-isolation/dirty-write.yaml:39 scenarios/mysql/02-isolation/dirty-write.yaml#steps[12].tl tl COMMIT M18 MySQL 8.4.11, InnoDB; before step: A=READ UNCOMMITTED, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=READ UNCOMMITTED, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/02-isolation/dirty-write.yaml#steps[12].tl at scenarios/mysql/02-isolation/dirty-write.yaml:39 C00485 base scenarios/mysql/02-isolation/dirty-write.yaml:41 scenarios/mysql/02-isolation/dirty-write.yaml#steps[13].A A SELECT id, price FROM items ORDER BY id M18 MySQL 8.4.11, InnoDB; before step: A=READ UNCOMMITTED, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ UNCOMMITTED, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/dirty-write.yaml#steps[13].A at scenarios/mysql/02-isolation/dirty-write.yaml:41 C00486 base scenarios/mysql/02-isolation/dirty-write.yaml:42 scenarios/mysql/02-isolation/dirty-write.yaml#steps[13].expect[0].id id 1 M18 MySQL 8.4.11, InnoDB; before step: A=READ UNCOMMITTED, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ UNCOMMITTED, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/dirty-write.yaml#steps[13].expect[0].id at scenarios/mysql/02-isolation/dirty-write.yaml:42 C00487 base scenarios/mysql/02-isolation/dirty-write.yaml:42 scenarios/mysql/02-isolation/dirty-write.yaml#steps[13].expect[0].price price 12 M18 MySQL 8.4.11, InnoDB; before step: A=READ UNCOMMITTED, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ UNCOMMITTED, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/dirty-write.yaml#steps[13].expect[0].price at scenarios/mysql/02-isolation/dirty-write.yaml:42 C00488 base scenarios/mysql/02-isolation/dirty-write.yaml:42 scenarios/mysql/02-isolation/dirty-write.yaml#steps[13].expect[1].id id 2 M18 MySQL 8.4.11, InnoDB; before step: A=READ UNCOMMITTED, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ UNCOMMITTED, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/dirty-write.yaml#steps[13].expect[1].id at scenarios/mysql/02-isolation/dirty-write.yaml:42 C00489 base scenarios/mysql/02-isolation/dirty-write.yaml:42 scenarios/mysql/02-isolation/dirty-write.yaml#steps[13].expect[1].price price 22 M18 MySQL 8.4.11, InnoDB; before step: A=READ UNCOMMITTED, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ UNCOMMITTED, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/dirty-write.yaml#steps[13].expect[1].price at scenarios/mysql/02-isolation/dirty-write.yaml:42 C00490 base scenarios/mysql/02-isolation/dirty-write.yaml:43 scenarios/mysql/02-isolation/dirty-write.yaml#steps[13].comment comment all B — as if B ran after A. Never 12/21 or 11/22. M18 MySQL 8.4.11, InnoDB; before step: A=READ UNCOMMITTED, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ UNCOMMITTED, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Replaced at the corresponding logical occurrence; current occurrence scenarios/mysql/02-isolation/dirty-write.yaml#steps[13].comment at scenarios/mysql/02-isolation/dirty-write.yaml:43 C00491 base scenarios/mysql/02-isolation/dirty-write.yaml:44 scenarios/mysql/02-isolation/dirty-write.yaml#steps[13].tl tl SELECT → 12, 22 (all B, never mixed) M18 MySQL 8.4.11, InnoDB; before step: A=READ UNCOMMITTED, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ UNCOMMITTED, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Replaced at the corresponding logical occurrence; current occurrence scenarios/mysql/02-isolation/dirty-write.yaml#steps[13].tl at scenarios/mysql/02-isolation/dirty-write.yaml:44 C00492 base scenarios/mysql/02-isolation/intermediate-read.yaml:1 scenarios/mysql/02-isolation/intermediate-read.yaml#title title READ UNCOMMITTED serves drafts that never become true M19 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Replaced at the corresponding logical occurrence; current occurrence scenarios/mysql/02-isolation/intermediate-read.yaml#title at scenarios/mysql/02-isolation/intermediate-read.yaml:1 C00493 base scenarios/mysql/02-isolation/intermediate-read.yaml:2 scenarios/mysql/02-isolation/intermediate-read.yaml#claim claim "At READ UNCOMMITTED a reader can observe an intermediate value the writer later overwrites before committing (Adya's G1b, ""intermediate read"") — a number that is never part of any committed state. READ COMMITTED stops this." M19 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Replaced at the corresponding logical occurrence; current occurrence scenarios/mysql/02-isolation/intermediate-read.yaml#claim at scenarios/mysql/02-isolation/intermediate-read.yaml:2 C00494 base scenarios/mysql/02-isolation/intermediate-read.yaml:6 scenarios/mysql/02-isolation/intermediate-read.yaml#anomaly anomaly G1b M19 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/intermediate-read.yaml#anomaly at scenarios/mysql/02-isolation/intermediate-read.yaml:7 C00495 base scenarios/mysql/02-isolation/intermediate-read.yaml:7 scenarios/mysql/02-isolation/intermediate-read.yaml#setup setup "CREATE TABLE accounts (id int PRIMARY KEY, owner varchar(20) NOT NULL, balance int NOT NULL); INSERT INTO accounts VALUES (1, 'alice', 100); " M19 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Replaced at the corresponding logical occurrence; current occurrence scenarios/mysql/02-isolation/intermediate-read.yaml#setup at scenarios/mysql/02-isolation/intermediate-read.yaml:8 C00496 base scenarios/mysql/02-isolation/intermediate-read.yaml:10 scenarios/mysql/02-isolation/intermediate-read.yaml#sessions[0] sessions[0] A M19 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/intermediate-read.yaml#sessions[0] at scenarios/mysql/02-isolation/intermediate-read.yaml:11 C00497 base scenarios/mysql/02-isolation/intermediate-read.yaml:10 scenarios/mysql/02-isolation/intermediate-read.yaml#sessions[1] sessions[1] B M19 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/intermediate-read.yaml#sessions[1] at scenarios/mysql/02-isolation/intermediate-read.yaml:11 C00498 base scenarios/mysql/02-isolation/intermediate-read.yaml:12 scenarios/mysql/02-isolation/intermediate-read.yaml#steps[0].note note A recalculates alice's balance in two steps. B watches at READ UNCOMMITTED. M19 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/02-isolation/intermediate-read.yaml#steps[0].note at scenarios/mysql/02-isolation/intermediate-read.yaml:13 C00499 base scenarios/mysql/02-isolation/intermediate-read.yaml:13 scenarios/mysql/02-isolation/intermediate-read.yaml#steps[1].B B SET SESSION TRANSACTION ISOLATION LEVEL READ UNCOMMITTED M19 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/intermediate-read.yaml#steps[1].B at scenarios/mysql/02-isolation/intermediate-read.yaml:14 C00500 base scenarios/mysql/02-isolation/intermediate-read.yaml:14 scenarios/mysql/02-isolation/intermediate-read.yaml#steps[2].B B BEGIN M19 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/intermediate-read.yaml#steps[2].B at scenarios/mysql/02-isolation/intermediate-read.yaml:15 C00501 base scenarios/mysql/02-isolation/intermediate-read.yaml:16 scenarios/mysql/02-isolation/intermediate-read.yaml#steps[3].A A BEGIN M19 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/intermediate-read.yaml#steps[3].A at scenarios/mysql/02-isolation/intermediate-read.yaml:17 C00502 base scenarios/mysql/02-isolation/intermediate-read.yaml:17 scenarios/mysql/02-isolation/intermediate-read.yaml#steps[4].A A UPDATE accounts SET balance = 999 WHERE id = 1 M19 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/intermediate-read.yaml#steps[4].A at scenarios/mysql/02-isolation/intermediate-read.yaml:18 C00503 base scenarios/mysql/02-isolation/intermediate-read.yaml:18 scenarios/mysql/02-isolation/intermediate-read.yaml#steps[4].comment comment a working draft — A isn't done yet M19 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Replaced at the corresponding logical occurrence; current occurrence scenarios/mysql/02-isolation/intermediate-read.yaml#steps[4].comment at scenarios/mysql/02-isolation/intermediate-read.yaml:19 C00504 base scenarios/mysql/02-isolation/intermediate-read.yaml:19 scenarios/mysql/02-isolation/intermediate-read.yaml#steps[4].tl tl UPDATE balance = 999 (a draft) M19 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/02-isolation/intermediate-read.yaml#steps[4].tl at scenarios/mysql/02-isolation/intermediate-read.yaml:20 C00505 base scenarios/mysql/02-isolation/intermediate-read.yaml:21 scenarios/mysql/02-isolation/intermediate-read.yaml#steps[5].B B SELECT balance FROM accounts WHERE id = 1 M19 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/intermediate-read.yaml#steps[5].B at scenarios/mysql/02-isolation/intermediate-read.yaml:22 C00506 base scenarios/mysql/02-isolation/intermediate-read.yaml:22 scenarios/mysql/02-isolation/intermediate-read.yaml#steps[5].expect[0].balance balance 999 M19 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/intermediate-read.yaml#steps[5].expect[0].balance at scenarios/mysql/02-isolation/intermediate-read.yaml:23 C00507 base scenarios/mysql/02-isolation/intermediate-read.yaml:23 scenarios/mysql/02-isolation/intermediate-read.yaml#steps[5].comment comment B just read a draft M19 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/02-isolation/intermediate-read.yaml#steps[5].comment at scenarios/mysql/02-isolation/intermediate-read.yaml:24 C00508 base scenarios/mysql/02-isolation/intermediate-read.yaml:24 scenarios/mysql/02-isolation/intermediate-read.yaml#steps[5].tl tl SELECT balance → 999 (reads the draft) M19 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/02-isolation/intermediate-read.yaml#steps[5].tl at scenarios/mysql/02-isolation/intermediate-read.yaml:25 C00509 base scenarios/mysql/02-isolation/intermediate-read.yaml:26 scenarios/mysql/02-isolation/intermediate-read.yaml#steps[6].A A UPDATE accounts SET balance = 110 WHERE id = 1 M19 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/intermediate-read.yaml#steps[6].A at scenarios/mysql/02-isolation/intermediate-read.yaml:27 C00510 base scenarios/mysql/02-isolation/intermediate-read.yaml:27 scenarios/mysql/02-isolation/intermediate-read.yaml#steps[6].comment comment A settles on the final value… M19 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/02-isolation/intermediate-read.yaml#steps[6].comment at scenarios/mysql/02-isolation/intermediate-read.yaml:28 C00511 base scenarios/mysql/02-isolation/intermediate-read.yaml:28 scenarios/mysql/02-isolation/intermediate-read.yaml#steps[6].tl tl UPDATE balance = 110 (final value) M19 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/02-isolation/intermediate-read.yaml#steps[6].tl at scenarios/mysql/02-isolation/intermediate-read.yaml:29 C00512 base scenarios/mysql/02-isolation/intermediate-read.yaml:29 scenarios/mysql/02-isolation/intermediate-read.yaml#steps[7].A A COMMIT M19 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/intermediate-read.yaml#steps[7].A at scenarios/mysql/02-isolation/intermediate-read.yaml:30 C00513 base scenarios/mysql/02-isolation/intermediate-read.yaml:30 scenarios/mysql/02-isolation/intermediate-read.yaml#steps[7].tl tl COMMIT M19 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/02-isolation/intermediate-read.yaml#steps[7].tl at scenarios/mysql/02-isolation/intermediate-read.yaml:31 C00514 base scenarios/mysql/02-isolation/intermediate-read.yaml:32 scenarios/mysql/02-isolation/intermediate-read.yaml#steps[8].B B SELECT balance FROM accounts WHERE id = 1 M19 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/intermediate-read.yaml#steps[8].B at scenarios/mysql/02-isolation/intermediate-read.yaml:33 C00515 base scenarios/mysql/02-isolation/intermediate-read.yaml:33 scenarios/mysql/02-isolation/intermediate-read.yaml#steps[8].expect[0].balance balance 110 M19 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/intermediate-read.yaml#steps[8].expect[0].balance at scenarios/mysql/02-isolation/intermediate-read.yaml:34 C00516 base scenarios/mysql/02-isolation/intermediate-read.yaml:34 scenarios/mysql/02-isolation/intermediate-read.yaml#steps[8].tl tl SELECT balance → 110 (999 was never real) M19 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Replaced at the corresponding logical occurrence; current occurrence scenarios/mysql/02-isolation/intermediate-read.yaml#steps[8].tl at scenarios/mysql/02-isolation/intermediate-read.yaml:35 C00517 base scenarios/mysql/02-isolation/intermediate-read.yaml:35 scenarios/mysql/02-isolation/intermediate-read.yaml#steps[9].B B COMMIT M19 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/intermediate-read.yaml#steps[9].B at scenarios/mysql/02-isolation/intermediate-read.yaml:36 C00518 base scenarios/mysql/02-isolation/intermediate-read.yaml:37 scenarios/mysql/02-isolation/intermediate-read.yaml#steps[10].note note The committed history is 100 → 110. The 999 B acted on was never true — not even for an instant of committed time. At READ COMMITTED the same watch shows only 100, then 110: M19 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Replaced at the corresponding logical occurrence; current occurrence scenarios/mysql/02-isolation/intermediate-read.yaml#steps[10].note at scenarios/mysql/02-isolation/intermediate-read.yaml:38 C00519 base scenarios/mysql/02-isolation/intermediate-read.yaml:41 scenarios/mysql/02-isolation/intermediate-read.yaml#steps[11].B B SET SESSION TRANSACTION ISOLATION LEVEL READ COMMITTED M19 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=READ COMMITTED, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/intermediate-read.yaml#steps[11].B at scenarios/mysql/02-isolation/intermediate-read.yaml:41 C00520 base scenarios/mysql/02-isolation/intermediate-read.yaml:42 scenarios/mysql/02-isolation/intermediate-read.yaml#steps[12].B B BEGIN M19 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=READ COMMITTED, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/intermediate-read.yaml#steps[12].B at scenarios/mysql/02-isolation/intermediate-read.yaml:42 C00521 base scenarios/mysql/02-isolation/intermediate-read.yaml:43 scenarios/mysql/02-isolation/intermediate-read.yaml#steps[13].A A BEGIN M19 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/intermediate-read.yaml#steps[13].A at scenarios/mysql/02-isolation/intermediate-read.yaml:43 C00522 base scenarios/mysql/02-isolation/intermediate-read.yaml:44 scenarios/mysql/02-isolation/intermediate-read.yaml#steps[14].A A UPDATE accounts SET balance = 555 WHERE id = 1 M19 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/intermediate-read.yaml#steps[14].A at scenarios/mysql/02-isolation/intermediate-read.yaml:44 C00523 base scenarios/mysql/02-isolation/intermediate-read.yaml:45 scenarios/mysql/02-isolation/intermediate-read.yaml#steps[15].B B SELECT balance FROM accounts WHERE id = 1 M19 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/intermediate-read.yaml#steps[15].B at scenarios/mysql/02-isolation/intermediate-read.yaml:45 C00524 base scenarios/mysql/02-isolation/intermediate-read.yaml:46 scenarios/mysql/02-isolation/intermediate-read.yaml#steps[15].expect[0].balance balance 110 M19 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/intermediate-read.yaml#steps[15].expect[0].balance at scenarios/mysql/02-isolation/intermediate-read.yaml:46 C00525 base scenarios/mysql/02-isolation/intermediate-read.yaml:47 scenarios/mysql/02-isolation/intermediate-read.yaml#steps[15].comment comment no drafts served here M19 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/02-isolation/intermediate-read.yaml#steps[15].comment at scenarios/mysql/02-isolation/intermediate-read.yaml:47 C00526 base scenarios/mysql/02-isolation/intermediate-read.yaml:48 scenarios/mysql/02-isolation/intermediate-read.yaml#steps[16].A A ROLLBACK M19 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/intermediate-read.yaml#steps[16].A at scenarios/mysql/02-isolation/intermediate-read.yaml:48 C00527 base scenarios/mysql/02-isolation/intermediate-read.yaml:49 scenarios/mysql/02-isolation/intermediate-read.yaml#steps[17].B B COMMIT M19 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=READ COMMITTED, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/intermediate-read.yaml#steps[17].B at scenarios/mysql/02-isolation/intermediate-read.yaml:49 C00528 base scenarios/mysql/02-isolation/lost-update-read-committed.yaml:1 scenarios/mysql/02-isolation/lost-update-read-committed.yaml#title title Lost update at READ COMMITTED M20 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/02-isolation/lost-update-read-committed.yaml#title at scenarios/mysql/02-isolation/lost-update-read-committed.yaml:1 C00529 base scenarios/mysql/02-isolation/lost-update-read-committed.yaml:2 scenarios/mysql/02-isolation/lost-update-read-committed.yaml#claim claim Two read-modify-write transactions at READ COMMITTED can silently overwrite each other: two deposits of 10 grow the balance by only 10. M20 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/02-isolation/lost-update-read-committed.yaml#claim at scenarios/mysql/02-isolation/lost-update-read-committed.yaml:2 C00530 base scenarios/mysql/02-isolation/lost-update-read-committed.yaml:5 scenarios/mysql/02-isolation/lost-update-read-committed.yaml#anomaly anomaly P4 M20 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/lost-update-read-committed.yaml#anomaly at scenarios/mysql/02-isolation/lost-update-read-committed.yaml:5 C00531 base scenarios/mysql/02-isolation/lost-update-read-committed.yaml:6 scenarios/mysql/02-isolation/lost-update-read-committed.yaml#isolation isolation READ COMMITTED M20 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/lost-update-read-committed.yaml#isolation at scenarios/mysql/02-isolation/lost-update-read-committed.yaml:6 C00532 base scenarios/mysql/02-isolation/lost-update-read-committed.yaml:7 scenarios/mysql/02-isolation/lost-update-read-committed.yaml#setup setup "CREATE TABLE accounts (id int PRIMARY KEY, owner varchar(20) NOT NULL, balance int NOT NULL); INSERT INTO accounts VALUES (1, 'alice', 100); " M20 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Replaced at the corresponding logical occurrence; current occurrence scenarios/mysql/02-isolation/lost-update-read-committed.yaml#setup at scenarios/mysql/02-isolation/lost-update-read-committed.yaml:7 C00533 base scenarios/mysql/02-isolation/lost-update-read-committed.yaml:10 scenarios/mysql/02-isolation/lost-update-read-committed.yaml#sessions[0] sessions[0] A M20 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/lost-update-read-committed.yaml#sessions[0] at scenarios/mysql/02-isolation/lost-update-read-committed.yaml:10 C00534 base scenarios/mysql/02-isolation/lost-update-read-committed.yaml:10 scenarios/mysql/02-isolation/lost-update-read-committed.yaml#sessions[1] sessions[1] B M20 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/lost-update-read-committed.yaml#sessions[1] at scenarios/mysql/02-isolation/lost-update-read-committed.yaml:10 C00535 base scenarios/mysql/02-isolation/lost-update-read-committed.yaml:12 scenarios/mysql/02-isolation/lost-update-read-committed.yaml#steps[0].note note Two app servers process a +10 deposit each: read the balance, add 10 in code, write it back. M20 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/02-isolation/lost-update-read-committed.yaml#steps[0].note at scenarios/mysql/02-isolation/lost-update-read-committed.yaml:12 C00536 base scenarios/mysql/02-isolation/lost-update-read-committed.yaml:15 scenarios/mysql/02-isolation/lost-update-read-committed.yaml#steps[1].A A SET TRANSACTION ISOLATION LEVEL READ COMMITTED M20 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/lost-update-read-committed.yaml#steps[1].A at scenarios/mysql/02-isolation/lost-update-read-committed.yaml:15 C00537 base scenarios/mysql/02-isolation/lost-update-read-committed.yaml:16 scenarios/mysql/02-isolation/lost-update-read-committed.yaml#steps[2].A A BEGIN M20 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/lost-update-read-committed.yaml#steps[2].A at scenarios/mysql/02-isolation/lost-update-read-committed.yaml:16 C00538 base scenarios/mysql/02-isolation/lost-update-read-committed.yaml:17 scenarios/mysql/02-isolation/lost-update-read-committed.yaml#steps[3].A A SELECT balance FROM accounts WHERE id = 1 M20 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/lost-update-read-committed.yaml#steps[3].A at scenarios/mysql/02-isolation/lost-update-read-committed.yaml:17 C00539 base scenarios/mysql/02-isolation/lost-update-read-committed.yaml:18 scenarios/mysql/02-isolation/lost-update-read-committed.yaml#steps[3].expect[0].balance balance 100 M20 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/lost-update-read-committed.yaml#steps[3].expect[0].balance at scenarios/mysql/02-isolation/lost-update-read-committed.yaml:18 C00540 base scenarios/mysql/02-isolation/lost-update-read-committed.yaml:19 scenarios/mysql/02-isolation/lost-update-read-committed.yaml#steps[3].capture capture readA M20 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/lost-update-read-committed.yaml#steps[3].capture at scenarios/mysql/02-isolation/lost-update-read-committed.yaml:19 C00541 base scenarios/mysql/02-isolation/lost-update-read-committed.yaml:20 scenarios/mysql/02-isolation/lost-update-read-committed.yaml#steps[3].tl tl SELECT balance → 100 M20 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/02-isolation/lost-update-read-committed.yaml#steps[3].tl at scenarios/mysql/02-isolation/lost-update-read-committed.yaml:20 C00542 base scenarios/mysql/02-isolation/lost-update-read-committed.yaml:22 scenarios/mysql/02-isolation/lost-update-read-committed.yaml#steps[4].B B SET TRANSACTION ISOLATION LEVEL READ COMMITTED M20 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, open transaction, autocommit=1; B=READ COMMITTED, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/lost-update-read-committed.yaml#steps[4].B at scenarios/mysql/02-isolation/lost-update-read-committed.yaml:22 C00543 base scenarios/mysql/02-isolation/lost-update-read-committed.yaml:23 scenarios/mysql/02-isolation/lost-update-read-committed.yaml#steps[5].B B BEGIN M20 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, open transaction, autocommit=1; B=READ COMMITTED, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, open transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/lost-update-read-committed.yaml#steps[5].B at scenarios/mysql/02-isolation/lost-update-read-committed.yaml:23 C00544 base scenarios/mysql/02-isolation/lost-update-read-committed.yaml:24 scenarios/mysql/02-isolation/lost-update-read-committed.yaml#steps[6].B B SELECT balance FROM accounts WHERE id = 1 M20 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, open transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, open transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/lost-update-read-committed.yaml#steps[6].B at scenarios/mysql/02-isolation/lost-update-read-committed.yaml:24 C00545 base scenarios/mysql/02-isolation/lost-update-read-committed.yaml:25 scenarios/mysql/02-isolation/lost-update-read-committed.yaml#steps[6].expect[0].balance balance 100 M20 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, open transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, open transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/lost-update-read-committed.yaml#steps[6].expect[0].balance at scenarios/mysql/02-isolation/lost-update-read-committed.yaml:25 C00546 base scenarios/mysql/02-isolation/lost-update-read-committed.yaml:26 scenarios/mysql/02-isolation/lost-update-read-committed.yaml#steps[6].capture capture readB M20 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, open transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, open transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/lost-update-read-committed.yaml#steps[6].capture at scenarios/mysql/02-isolation/lost-update-read-committed.yaml:26 C00547 base scenarios/mysql/02-isolation/lost-update-read-committed.yaml:27 scenarios/mysql/02-isolation/lost-update-read-committed.yaml#steps[6].comment comment B reads the same 100 — A hasn't committed M20 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, open transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, open transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Replaced at the corresponding logical occurrence; current occurrence scenarios/mysql/02-isolation/lost-update-read-committed.yaml#steps[6].comment at scenarios/mysql/02-isolation/lost-update-read-committed.yaml:27 C00548 base scenarios/mysql/02-isolation/lost-update-read-committed.yaml:28 scenarios/mysql/02-isolation/lost-update-read-committed.yaml#steps[6].tl tl SELECT balance → 100 (same stale read) M20 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, open transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, open transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/02-isolation/lost-update-read-committed.yaml#steps[6].tl at scenarios/mysql/02-isolation/lost-update-read-committed.yaml:28 C00549 base scenarios/mysql/02-isolation/lost-update-read-committed.yaml:30 scenarios/mysql/02-isolation/lost-update-read-committed.yaml#steps[7].A A UPDATE accounts SET balance = ${readA.balance} + 10 WHERE id = 1 M20 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, open transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, open transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/lost-update-read-committed.yaml#steps[7].A at scenarios/mysql/02-isolation/lost-update-read-committed.yaml:30 C00550 base scenarios/mysql/02-isolation/lost-update-read-committed.yaml:31 scenarios/mysql/02-isolation/lost-update-read-committed.yaml#steps[7].tl tl UPDATE balance = 100 + 10 M20 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, open transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, open transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/02-isolation/lost-update-read-committed.yaml#steps[7].tl at scenarios/mysql/02-isolation/lost-update-read-committed.yaml:31 C00551 base scenarios/mysql/02-isolation/lost-update-read-committed.yaml:32 scenarios/mysql/02-isolation/lost-update-read-committed.yaml#steps[8].A A COMMIT M20 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, open transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/lost-update-read-committed.yaml#steps[8].A at scenarios/mysql/02-isolation/lost-update-read-committed.yaml:32 C00552 base scenarios/mysql/02-isolation/lost-update-read-committed.yaml:33 scenarios/mysql/02-isolation/lost-update-read-committed.yaml#steps[8].tl tl COMMIT M20 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, open transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/02-isolation/lost-update-read-committed.yaml#steps[8].tl at scenarios/mysql/02-isolation/lost-update-read-committed.yaml:33 C00553 base scenarios/mysql/02-isolation/lost-update-read-committed.yaml:35 scenarios/mysql/02-isolation/lost-update-read-committed.yaml#steps[9].note note B computed 100 + 10 from its stale read. Nothing stops the write — A's transaction is long gone. M20 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Replaced at the corresponding logical occurrence; current occurrence scenarios/mysql/02-isolation/lost-update-read-committed.yaml#steps[9].note at scenarios/mysql/02-isolation/lost-update-read-committed.yaml:35 C00554 base scenarios/mysql/02-isolation/lost-update-read-committed.yaml:36 scenarios/mysql/02-isolation/lost-update-read-committed.yaml#steps[10].B B UPDATE accounts SET balance = ${readB.balance} + 10 WHERE id = 1 M20 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/lost-update-read-committed.yaml#steps[10].B at scenarios/mysql/02-isolation/lost-update-read-committed.yaml:36 C00555 base scenarios/mysql/02-isolation/lost-update-read-committed.yaml:37 scenarios/mysql/02-isolation/lost-update-read-committed.yaml#steps[10].tl tl UPDATE balance = 100 + 10 (stale math) M20 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/02-isolation/lost-update-read-committed.yaml#steps[10].tl at scenarios/mysql/02-isolation/lost-update-read-committed.yaml:37 C00556 base scenarios/mysql/02-isolation/lost-update-read-committed.yaml:38 scenarios/mysql/02-isolation/lost-update-read-committed.yaml#steps[11].B B COMMIT M20 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/lost-update-read-committed.yaml#steps[11].B at scenarios/mysql/02-isolation/lost-update-read-committed.yaml:38 C00557 base scenarios/mysql/02-isolation/lost-update-read-committed.yaml:39 scenarios/mysql/02-isolation/lost-update-read-committed.yaml#steps[11].tl tl COMMIT M20 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/02-isolation/lost-update-read-committed.yaml#steps[11].tl at scenarios/mysql/02-isolation/lost-update-read-committed.yaml:39 C00558 base scenarios/mysql/02-isolation/lost-update-read-committed.yaml:41 scenarios/mysql/02-isolation/lost-update-read-committed.yaml#steps[12].A A SELECT balance FROM accounts WHERE id = 1 M20 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/lost-update-read-committed.yaml#steps[12].A at scenarios/mysql/02-isolation/lost-update-read-committed.yaml:41 C00559 base scenarios/mysql/02-isolation/lost-update-read-committed.yaml:42 scenarios/mysql/02-isolation/lost-update-read-committed.yaml#steps[12].expect[0].balance balance 110 M20 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/lost-update-read-committed.yaml#steps[12].expect[0].balance at scenarios/mysql/02-isolation/lost-update-read-committed.yaml:42 C00560 base scenarios/mysql/02-isolation/lost-update-read-committed.yaml:43 scenarios/mysql/02-isolation/lost-update-read-committed.yaml#steps[12].comment comment two +10 deposits, but only one survived M20 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/02-isolation/lost-update-read-committed.yaml#steps[12].comment at scenarios/mysql/02-isolation/lost-update-read-committed.yaml:43 C00561 base scenarios/mysql/02-isolation/lost-update-read-committed.yaml:44 scenarios/mysql/02-isolation/lost-update-read-committed.yaml#steps[12].tl tl SELECT balance → 110 — one deposit gone M20 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Replaced at the corresponding logical occurrence; current occurrence scenarios/mysql/02-isolation/lost-update-read-committed.yaml#steps[12].tl at scenarios/mysql/02-isolation/lost-update-read-committed.yaml:44 C00562 base scenarios/mysql/02-isolation/lost-update-read-committed.yaml:46 scenarios/mysql/02-isolation/lost-update-read-committed.yaml#steps[13].note note A's deposit vanished without any error. Fixes: atomic UPDATE or SELECT FOR UPDATE — see the lesson. M20 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Replaced at the corresponding logical occurrence; current occurrence scenarios/mysql/02-isolation/lost-update-read-committed.yaml#steps[13].note at scenarios/mysql/02-isolation/lost-update-read-committed.yaml:46 C00563 base scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml:1 scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml#title title REPEATABLE READ does NOT stop lost updates M21 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml#title at scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml:1 C00564 base scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml:2 scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml#claim claim The interleaving that loses an update at READ COMMITTED loses it at REPEATABLE READ too — MySQL raises no error, unlike PostgreSQL's 40001. The fix must be a locking read or an atomic UPDATE. M21 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Replaced at the corresponding logical occurrence; current occurrence scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml#claim at scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml:2 C00565 base scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml:6 scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml#anomaly anomaly P4 M21 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml#anomaly at scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml:6 C00566 base scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml:7 scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml#setup setup "CREATE TABLE accounts (id int PRIMARY KEY, owner varchar(20) NOT NULL, balance int NOT NULL); INSERT INTO accounts VALUES (1, 'alice', 100); " M21 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Replaced at the corresponding logical occurrence; current occurrence scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml#setup at scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml:8 C00567 base scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml:10 scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml#sessions[0] sessions[0] A M21 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml#sessions[0] at scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml:11 C00568 base scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml:10 scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml#sessions[1] sessions[1] B M21 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml#sessions[1] at scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml:11 C00569 base scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml:12 scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml#steps[0].note note The same two +10 deposits — this time at REPEATABLE READ, MySQL's default. M21 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Replaced at the corresponding logical occurrence; current occurrence scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml#steps[0].note at scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml:13 C00570 base scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml:13 scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml#steps[1].A A BEGIN M21 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml#steps[3].A at scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml:16 C00571 base scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml:14 scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml#steps[2].A A SELECT balance FROM accounts WHERE id = 1 M21 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml#steps[4].A at scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml:17 C00572 base scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml:15 scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml#steps[2].capture capture readA M21 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml#steps[4].capture at scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml:19 C00573 base scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml:16 scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml#steps[2].tl tl SELECT balance → 100 M21 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml#steps[4].tl at scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml:20 C00574 base scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml:18 scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml#steps[3].B B BEGIN M21 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml#steps[5].B at scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml:22 C00575 base scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml:19 scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml#steps[4].B B SELECT balance FROM accounts WHERE id = 1 M21 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml#steps[6].B at scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml:23 C00576 base scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml:20 scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml#steps[4].expect[0].balance balance 100 M21 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml#steps[6].expect[0].balance at scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml:24 C00577 base scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml:21 scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml#steps[4].capture capture readB M21 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml#steps[6].capture at scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml:25 C00578 base scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml:22 scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml#steps[4].tl tl SELECT balance → 100 (same snapshot) M21 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml#steps[6].tl at scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml:26 C00579 base scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml:24 scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml#steps[5].A A UPDATE accounts SET balance = ${readA.balance} + 10 WHERE id = 1 M21 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml#steps[7].A at scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml:28 C00580 base scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml:25 scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml#steps[5].tl tl UPDATE balance = 100 + 10 M21 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml#steps[7].tl at scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml:29 C00581 base scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml:26 scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml#steps[6].A A COMMIT M21 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml#steps[8].A at scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml:30 C00582 base scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml:27 scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml#steps[6].tl tl COMMIT M21 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml#steps[8].tl at scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml:31 C00583 base scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml:29 scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml#steps[7].note note B's snapshot predates A's commit — but MySQL's UPDATE acts on the CURRENT row and raises nothing. M21 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Replaced at the corresponding logical occurrence; current occurrence scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml#steps[9].note at scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml:33 C00584 base scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml:30 scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml#steps[8].B B UPDATE accounts SET balance = ${readB.balance} + 10 WHERE id = 1 M21 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml#steps[10].B at scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml:34 C00585 base scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml:31 scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml#steps[8].tl tl UPDATE balance = 100 + 10 — no error! M21 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Replaced at the corresponding logical occurrence; current occurrence scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml#steps[10].tl at scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml:35 C00586 base scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml:32 scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml#steps[9].B B COMMIT M21 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml#steps[11].B at scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml:36 C00587 base scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml:33 scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml#steps[9].tl tl COMMIT M21 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml#steps[11].tl at scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml:37 C00588 base scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml:35 scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml#steps[10].A A SELECT balance FROM accounts WHERE id = 1 M21 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml#steps[12].A at scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml:39 C00589 base scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml:36 scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml#steps[10].expect[0].balance balance 110 M21 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml#steps[12].expect[0].balance at scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml:40 C00590 base scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml:37 scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml#steps[10].comment comment A's deposit is gone — silently, even at REPEATABLE READ M21 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Replaced at the corresponding logical occurrence; current occurrence scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml#steps[12].comment at scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml:41 C00591 base scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml:38 scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml#steps[10].tl tl SELECT balance → 110 — deposit gone, silently M21 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Replaced at the corresponding logical occurrence; current occurrence scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml#steps[12].tl at scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml:42 C00592 base scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml:40 scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml#steps[11].note note PostgreSQL refuses B's write here (SQLSTATE 40001). MySQL does not — don't port that assumption. M21 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Replaced at the corresponding logical occurrence; current occurrence scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml#steps[13].note at scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml:44 C00593 base scenarios/mysql/02-isolation/non-repeatable-read.yaml:1 scenarios/mysql/02-isolation/non-repeatable-read.yaml#title title Non-repeatable read under READ COMMITTED M22 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/02-isolation/non-repeatable-read.yaml#title at scenarios/mysql/02-isolation/non-repeatable-read.yaml:1 C00594 base scenarios/mysql/02-isolation/non-repeatable-read.yaml:2 scenarios/mysql/02-isolation/non-repeatable-read.yaml#claim claim At READ COMMITTED, a transaction can read two different values for the same row — other transactions' commits become visible between its statements. M22 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Replaced at the corresponding logical occurrence; current occurrence scenarios/mysql/02-isolation/non-repeatable-read.yaml#claim at scenarios/mysql/02-isolation/non-repeatable-read.yaml:2 C00595 base scenarios/mysql/02-isolation/non-repeatable-read.yaml:5 scenarios/mysql/02-isolation/non-repeatable-read.yaml#anomaly anomaly P2 M22 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/non-repeatable-read.yaml#anomaly at scenarios/mysql/02-isolation/non-repeatable-read.yaml:5 C00596 base scenarios/mysql/02-isolation/non-repeatable-read.yaml:6 scenarios/mysql/02-isolation/non-repeatable-read.yaml#isolation isolation READ COMMITTED M22 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/non-repeatable-read.yaml#isolation at scenarios/mysql/02-isolation/non-repeatable-read.yaml:6 C00597 base scenarios/mysql/02-isolation/non-repeatable-read.yaml:7 scenarios/mysql/02-isolation/non-repeatable-read.yaml#setup setup "CREATE TABLE accounts (id int PRIMARY KEY, owner varchar(20) NOT NULL, balance int NOT NULL); INSERT INTO accounts VALUES (1, 'alice', 100); " M22 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Replaced at the corresponding logical occurrence; current occurrence scenarios/mysql/02-isolation/non-repeatable-read.yaml#setup at scenarios/mysql/02-isolation/non-repeatable-read.yaml:7 C00598 base scenarios/mysql/02-isolation/non-repeatable-read.yaml:10 scenarios/mysql/02-isolation/non-repeatable-read.yaml#sessions[0] sessions[0] A M22 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/non-repeatable-read.yaml#sessions[0] at scenarios/mysql/02-isolation/non-repeatable-read.yaml:10 C00599 base scenarios/mysql/02-isolation/non-repeatable-read.yaml:10 scenarios/mysql/02-isolation/non-repeatable-read.yaml#sessions[1] sessions[1] B M22 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/non-repeatable-read.yaml#sessions[1] at scenarios/mysql/02-isolation/non-repeatable-read.yaml:10 C00600 base scenarios/mysql/02-isolation/non-repeatable-read.yaml:12 scenarios/mysql/02-isolation/non-repeatable-read.yaml#steps[0].A A SET TRANSACTION ISOLATION LEVEL READ COMMITTED M22 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/non-repeatable-read.yaml#steps[0].A at scenarios/mysql/02-isolation/non-repeatable-read.yaml:12 C00601 base scenarios/mysql/02-isolation/non-repeatable-read.yaml:13 scenarios/mysql/02-isolation/non-repeatable-read.yaml#steps[1].A A BEGIN M22 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/non-repeatable-read.yaml#steps[1].A at scenarios/mysql/02-isolation/non-repeatable-read.yaml:13 C00602 base scenarios/mysql/02-isolation/non-repeatable-read.yaml:14 scenarios/mysql/02-isolation/non-repeatable-read.yaml#steps[2].A A SELECT balance FROM accounts WHERE id = 1 M22 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/non-repeatable-read.yaml#steps[2].A at scenarios/mysql/02-isolation/non-repeatable-read.yaml:14 C00603 base scenarios/mysql/02-isolation/non-repeatable-read.yaml:15 scenarios/mysql/02-isolation/non-repeatable-read.yaml#steps[2].expect[0].balance balance 100 M22 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/non-repeatable-read.yaml#steps[2].expect[0].balance at scenarios/mysql/02-isolation/non-repeatable-read.yaml:15 C00604 base scenarios/mysql/02-isolation/non-repeatable-read.yaml:16 scenarios/mysql/02-isolation/non-repeatable-read.yaml#steps[2].tl tl SELECT balance → 100 M22 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/02-isolation/non-repeatable-read.yaml#steps[2].tl at scenarios/mysql/02-isolation/non-repeatable-read.yaml:16 C00605 base scenarios/mysql/02-isolation/non-repeatable-read.yaml:18 scenarios/mysql/02-isolation/non-repeatable-read.yaml#steps[3].note note While A's transaction is still open, B updates the row and commits. M22 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/02-isolation/non-repeatable-read.yaml#steps[3].note at scenarios/mysql/02-isolation/non-repeatable-read.yaml:18 C00606 base scenarios/mysql/02-isolation/non-repeatable-read.yaml:19 scenarios/mysql/02-isolation/non-repeatable-read.yaml#steps[4].B B UPDATE accounts SET balance = 200 WHERE id = 1 M22 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/non-repeatable-read.yaml#steps[4].B at scenarios/mysql/02-isolation/non-repeatable-read.yaml:19 C00607 base scenarios/mysql/02-isolation/non-repeatable-read.yaml:20 scenarios/mysql/02-isolation/non-repeatable-read.yaml#steps[4].tl tl UPDATE balance = 200 (autocommit) M22 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/02-isolation/non-repeatable-read.yaml#steps[4].tl at scenarios/mysql/02-isolation/non-repeatable-read.yaml:20 C00608 base scenarios/mysql/02-isolation/non-repeatable-read.yaml:22 scenarios/mysql/02-isolation/non-repeatable-read.yaml#steps[5].A A SELECT balance FROM accounts WHERE id = 1 M22 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/non-repeatable-read.yaml#steps[5].A at scenarios/mysql/02-isolation/non-repeatable-read.yaml:22 C00609 base scenarios/mysql/02-isolation/non-repeatable-read.yaml:23 scenarios/mysql/02-isolation/non-repeatable-read.yaml#steps[5].expect[0].balance balance 200 M22 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/non-repeatable-read.yaml#steps[5].expect[0].balance at scenarios/mysql/02-isolation/non-repeatable-read.yaml:23 C00610 base scenarios/mysql/02-isolation/non-repeatable-read.yaml:24 scenarios/mysql/02-isolation/non-repeatable-read.yaml#steps[5].comment comment same query, same transaction — different answer M22 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Replaced at the corresponding logical occurrence; current occurrence scenarios/mysql/02-isolation/non-repeatable-read.yaml#steps[5].comment at scenarios/mysql/02-isolation/non-repeatable-read.yaml:24 C00611 base scenarios/mysql/02-isolation/non-repeatable-read.yaml:25 scenarios/mysql/02-isolation/non-repeatable-read.yaml#steps[5].tl tl SELECT balance → 200 — same txn, different answer M22 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Replaced at the corresponding logical occurrence; current occurrence scenarios/mysql/02-isolation/non-repeatable-read.yaml#steps[5].tl at scenarios/mysql/02-isolation/non-repeatable-read.yaml:25 C00612 base scenarios/mysql/02-isolation/non-repeatable-read.yaml:26 scenarios/mysql/02-isolation/non-repeatable-read.yaml#steps[6].A A COMMIT M22 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/non-repeatable-read.yaml#steps[6].A at scenarios/mysql/02-isolation/non-repeatable-read.yaml:26 C00613 base scenarios/mysql/02-isolation/non-repeatable-read.yaml:28 scenarios/mysql/02-isolation/non-repeatable-read.yaml#steps[7].note note Readers never block — but writers do. The same interleaving with UPDATEs makes B wait for A's row lock. M22 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Replaced at the corresponding logical occurrence; current occurrence scenarios/mysql/02-isolation/non-repeatable-read.yaml#steps[7].note at scenarios/mysql/02-isolation/non-repeatable-read.yaml:28 C00614 base scenarios/mysql/02-isolation/non-repeatable-read.yaml:31 scenarios/mysql/02-isolation/non-repeatable-read.yaml#steps[8].A A BEGIN M22 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/non-repeatable-read.yaml#steps[8].A at scenarios/mysql/02-isolation/non-repeatable-read.yaml:31 C00615 base scenarios/mysql/02-isolation/non-repeatable-read.yaml:32 scenarios/mysql/02-isolation/non-repeatable-read.yaml#steps[9].A A UPDATE accounts SET balance = 300 WHERE id = 1 M22 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/non-repeatable-read.yaml#steps[9].A at scenarios/mysql/02-isolation/non-repeatable-read.yaml:32 C00616 base scenarios/mysql/02-isolation/non-repeatable-read.yaml:34 scenarios/mysql/02-isolation/non-repeatable-read.yaml#steps[10].B B UPDATE accounts SET balance = 400 WHERE id = 1 M22 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/non-repeatable-read.yaml#steps[10].B at scenarios/mysql/02-isolation/non-repeatable-read.yaml:34 C00617 base scenarios/mysql/02-isolation/non-repeatable-read.yaml:35 scenarios/mysql/02-isolation/non-repeatable-read.yaml#steps[10].blocks blocks p1 M22 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/non-repeatable-read.yaml#steps[10].blocks at scenarios/mysql/02-isolation/non-repeatable-read.yaml:35 C00618 base scenarios/mysql/02-isolation/non-repeatable-read.yaml:37 scenarios/mysql/02-isolation/non-repeatable-read.yaml#steps[11].A A COMMIT M22 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/non-repeatable-read.yaml#steps[11].A at scenarios/mysql/02-isolation/non-repeatable-read.yaml:37 C00619 base scenarios/mysql/02-isolation/non-repeatable-read.yaml:38 scenarios/mysql/02-isolation/non-repeatable-read.yaml#steps[11].comment comment releases the row lock M22 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/02-isolation/non-repeatable-read.yaml#steps[11].comment at scenarios/mysql/02-isolation/non-repeatable-read.yaml:38 C00620 base scenarios/mysql/02-isolation/non-repeatable-read.yaml:39 scenarios/mysql/02-isolation/non-repeatable-read.yaml#steps[12].success success p1 M22 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/non-repeatable-read.yaml#steps[12].success at scenarios/mysql/02-isolation/non-repeatable-read.yaml:39 C00621 base scenarios/mysql/02-isolation/non-repeatable-read.yaml:41 scenarios/mysql/02-isolation/non-repeatable-read.yaml#steps[13].B B SELECT balance FROM accounts WHERE id = 1 M22 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/non-repeatable-read.yaml#steps[13].B at scenarios/mysql/02-isolation/non-repeatable-read.yaml:42 C00622 base scenarios/mysql/02-isolation/non-repeatable-read.yaml:42 scenarios/mysql/02-isolation/non-repeatable-read.yaml#steps[13].expect[0].balance balance 400 M22 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/non-repeatable-read.yaml#steps[13].expect[0].balance at scenarios/mysql/02-isolation/non-repeatable-read.yaml:43 C00623 base scenarios/mysql/02-isolation/non-repeatable-read.yaml:43 scenarios/mysql/02-isolation/non-repeatable-read.yaml#steps[13].comment comment B's write landed on top of A's committed 300 M22 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/02-isolation/non-repeatable-read.yaml#steps[13].comment at scenarios/mysql/02-isolation/non-repeatable-read.yaml:44 C00624 base scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:1 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#title title A committed transaction can half-vanish at READ UNCOMMITTED M23 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#title at scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:1 C00625 base scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:2 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#claim claim "At READ UNCOMMITTED a reader can see a later transaction's uncommitted overwrite of one row while relying on the overwritten transaction's other row (Adya's OTV, ""observed transaction vanishes"") — the committed transaction is visible only in pieces. READ COMMITTED restores atomic visibility." M23 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Replaced at the corresponding logical occurrence; current occurrence scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#claim at scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:2 C00626 base scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:8 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#anomaly anomaly OTV M23 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#anomaly at scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:9 C00627 base scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:9 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#setup setup "CREATE TABLE accounts (id int PRIMARY KEY, owner varchar(20) NOT NULL, balance int NOT NULL); INSERT INTO accounts VALUES (1, 'alice', 100), (2, 'bob', 100); " M23 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Replaced at the corresponding logical occurrence; current occurrence scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#setup at scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:10 C00628 base scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:12 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#sessions[0] sessions[0] A M23 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#sessions[0] at scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:13 C00629 base scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:12 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#sessions[1] sessions[1] B M23 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#sessions[1] at scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:13 C00630 base scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:12 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#sessions[2] sessions[2] C M23 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#sessions[2] at scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:13 C00631 base scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:14 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[0].note note A rewrites both balances and commits. B overwrites one of them. C watches — dirtily. M23 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Replaced at the corresponding logical occurrence; current occurrence scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[0].note at scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:15 C00632 base scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:15 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[1].C C SET SESSION TRANSACTION ISOLATION LEVEL READ UNCOMMITTED M23 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ UNCOMMITTED, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[1].C at scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:16 C00633 base scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:16 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[2].C C BEGIN M23 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ UNCOMMITTED, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ UNCOMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[2].C at scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:17 C00634 base scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:18 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[3].A A BEGIN M23 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ UNCOMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[3].A at scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:19 C00635 base scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:19 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[4].A A UPDATE accounts SET balance = 11 WHERE id = 1 M23 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ UNCOMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[4].A at scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:20 C00636 base scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:20 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[4].tl tl id1 = 11 M23 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ UNCOMMITTED, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[4].tl at scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:21 C00637 base scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:21 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[5].A A UPDATE accounts SET balance = 19 WHERE id = 2 M23 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ UNCOMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[5].A at scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:22 C00638 base scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:22 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[5].tl tl id2 = 19 M23 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ UNCOMMITTED, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[5].tl at scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:23 C00639 base scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:24 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[6].B B BEGIN M23 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; C=READ UNCOMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[6].B at scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:25 C00640 base scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:25 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[7].B B UPDATE accounts SET balance = 12 WHERE id = 1 M23 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; C=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; C=READ UNCOMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[7].B at scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:26 C00641 base scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:26 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[7].blocks blocks p1 M23 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; C=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; C=READ UNCOMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[7].blocks at scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:27 C00642 base scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:27 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[7].tl tl UPDATE id1 = 12 M23 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; C=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; C=READ UNCOMMITTED, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[7].tl at scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:28 C00643 base scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:28 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[8].A A COMMIT M23 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; C=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; C=READ UNCOMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[8].A at scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:29 C00644 base scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:29 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[8].comment comment A is committed — its writes are 11 and 19 M23 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; C=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; C=READ UNCOMMITTED, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Replaced at the corresponding logical occurrence; current occurrence scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[8].comment at scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:30 C00645 base scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:30 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[8].tl tl COMMIT (11 and 19) M23 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; C=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; C=READ UNCOMMITTED, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[8].tl at scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:31 C00646 base scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:31 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[9].success success p1 M23 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; C=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; C=READ UNCOMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[9].success at scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:32 C00647 base scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:33 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[10].C C SELECT id, balance FROM accounts ORDER BY id M23 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; C=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; C=READ UNCOMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[10].C at scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:34 C00648 base scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:34 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[10].expect[0].id id 1 M23 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; C=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; C=READ UNCOMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[10].expect[0].id at scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:35 C00649 base scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:34 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[10].expect[0].balance balance 12 M23 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; C=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; C=READ UNCOMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[10].expect[0].balance at scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:35 C00650 base scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:34 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[10].expect[1].id id 2 M23 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; C=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; C=READ UNCOMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[10].expect[1].id at scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:35 C00651 base scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:34 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[10].expect[1].balance balance 19 M23 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; C=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; C=READ UNCOMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[10].expect[1].balance at scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:35 C00652 base scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:35 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[10].comment comment 12 is B's uncommitted draft, 19 is A's commit — A's 11 already vanished M23 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; C=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; C=READ UNCOMMITTED, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Replaced at the corresponding logical occurrence; current occurrence scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[10].comment at scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:36 C00653 base scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:36 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[10].tl tl C reads → 12, 19 (A's 11 already gone) M23 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; C=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; C=READ UNCOMMITTED, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[10].tl at scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:37 C00654 base scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:38 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[11].note note C never saw the committed state {11, 19}. Half of A was overwritten before C ever observed it — as far as C can tell, A only ever wrote one row. B now finishes: M23 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; C=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; C=READ UNCOMMITTED, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Replaced at the corresponding logical occurrence; current occurrence scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[11].note at scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:39 C00655 base scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:42 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[12].B B UPDATE accounts SET balance = 18 WHERE id = 2 M23 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; C=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; C=READ UNCOMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[12].B at scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:43 C00656 base scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:43 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[13].B B COMMIT M23 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; C=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ UNCOMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[13].B at scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:44 C00657 base scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:44 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[14].C C SELECT id, balance FROM accounts ORDER BY id M23 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ UNCOMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[14].C at scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:45 C00658 base scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:45 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[14].expect[0].id id 1 M23 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ UNCOMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[14].expect[0].id at scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:46 C00659 base scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:45 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[14].expect[0].balance balance 12 M23 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ UNCOMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[14].expect[0].balance at scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:46 C00660 base scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:45 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[14].expect[1].id id 2 M23 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ UNCOMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[14].expect[1].id at scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:46 C00661 base scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:45 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[14].expect[1].balance balance 18 M23 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ UNCOMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[14].expect[1].balance at scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:46 C00662 base scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:46 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[15].C C COMMIT M23 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ UNCOMMITTED, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[15].C at scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:47 C00663 base scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:48 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[16].note note READ COMMITTED never shows a committed transaction in pieces: M23 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ UNCOMMITTED, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ UNCOMMITTED, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Replaced at the corresponding logical occurrence; current occurrence scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[16].note at scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:49 C00664 base scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:49 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[17].C C SET SESSION TRANSACTION ISOLATION LEVEL READ COMMITTED M23 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ UNCOMMITTED, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ COMMITTED, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[17].C at scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:50 C00665 base scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:50 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[18].C C BEGIN M23 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ COMMITTED, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ COMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[18].C at scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:51 C00666 base scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:51 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[19].A A BEGIN M23 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ COMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ COMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[19].A at scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:52 C00667 base scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:52 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[20].A A UPDATE accounts SET balance = 51 WHERE id = 1 M23 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ COMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ COMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[20].A at scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:53 C00668 base scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:53 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[21].A A UPDATE accounts SET balance = 59 WHERE id = 2 M23 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ COMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ COMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[21].A at scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:54 C00669 base scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:54 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[22].C C SELECT id, balance FROM accounts ORDER BY id M23 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ COMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ COMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[22].C at scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:55 C00670 base scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:55 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[22].expect[0].id id 1 M23 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ COMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ COMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[22].expect[0].id at scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:56 C00671 base scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:55 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[22].expect[0].balance balance 12 M23 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ COMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ COMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[22].expect[0].balance at scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:56 C00672 base scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:55 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[22].expect[1].id id 2 M23 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ COMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ COMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[22].expect[1].id at scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:56 C00673 base scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:55 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[22].expect[1].balance balance 18 M23 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ COMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ COMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[22].expect[1].balance at scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:56 C00674 base scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:56 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[22].comment comment all of the last committed state — nothing of A's draft M23 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ COMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ COMMITTED, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Replaced at the corresponding logical occurrence; current occurrence scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[22].comment at scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:57 C00675 base scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:57 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[23].A A COMMIT M23 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ COMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ COMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[23].A at scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:58 C00676 base scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:58 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[24].C C SELECT id, balance FROM accounts ORDER BY id M23 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ COMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ COMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[24].C at scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:59 C00677 base scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:59 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[24].expect[0].id id 1 M23 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ COMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ COMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[24].expect[0].id at scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:60 C00678 base scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:59 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[24].expect[0].balance balance 51 M23 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ COMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ COMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[24].expect[0].balance at scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:60 C00679 base scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:59 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[24].expect[1].id id 2 M23 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ COMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ COMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[24].expect[1].id at scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:60 C00680 base scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:59 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[24].expect[1].balance balance 59 M23 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ COMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ COMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[24].expect[1].balance at scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:60 C00681 base scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:60 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[24].comment comment and now all of A, atomically M23 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ COMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ COMMITTED, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[24].comment at scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:61 C00682 base scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:61 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[25].C C COMMIT M23 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ COMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ COMMITTED, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[25].C at scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:62 C00683 base scenarios/mysql/02-isolation/phantom-read.yaml:1 scenarios/mysql/02-isolation/phantom-read.yaml#title title Phantom read under READ COMMITTED M24 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/02-isolation/phantom-read.yaml#title at scenarios/mysql/02-isolation/phantom-read.yaml:1 C00684 base scenarios/mysql/02-isolation/phantom-read.yaml:2 scenarios/mysql/02-isolation/phantom-read.yaml#claim claim At READ COMMITTED, re-running the same range query inside one transaction can return rows that weren't there before — phantoms. M24 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Replaced at the corresponding logical occurrence; current occurrence scenarios/mysql/02-isolation/phantom-read.yaml#claim at scenarios/mysql/02-isolation/phantom-read.yaml:2 C00685 base scenarios/mysql/02-isolation/phantom-read.yaml:5 scenarios/mysql/02-isolation/phantom-read.yaml#anomaly anomaly PMP M24 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/phantom-read.yaml#anomaly at scenarios/mysql/02-isolation/phantom-read.yaml:5 C00686 base scenarios/mysql/02-isolation/phantom-read.yaml:6 scenarios/mysql/02-isolation/phantom-read.yaml#isolation isolation READ COMMITTED M24 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/phantom-read.yaml#isolation at scenarios/mysql/02-isolation/phantom-read.yaml:6 C00687 base scenarios/mysql/02-isolation/phantom-read.yaml:7 scenarios/mysql/02-isolation/phantom-read.yaml#setup setup "CREATE TABLE orders (id int PRIMARY KEY, amount int NOT NULL); INSERT INTO orders VALUES (1, 500), (2, 300); " M24 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Replaced at the corresponding logical occurrence; current occurrence scenarios/mysql/02-isolation/phantom-read.yaml#setup at scenarios/mysql/02-isolation/phantom-read.yaml:7 C00688 base scenarios/mysql/02-isolation/phantom-read.yaml:10 scenarios/mysql/02-isolation/phantom-read.yaml#sessions[0] sessions[0] A M24 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/phantom-read.yaml#sessions[0] at scenarios/mysql/02-isolation/phantom-read.yaml:10 C00689 base scenarios/mysql/02-isolation/phantom-read.yaml:10 scenarios/mysql/02-isolation/phantom-read.yaml#sessions[1] sessions[1] B M24 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/phantom-read.yaml#sessions[1] at scenarios/mysql/02-isolation/phantom-read.yaml:10 C00690 base scenarios/mysql/02-isolation/phantom-read.yaml:12 scenarios/mysql/02-isolation/phantom-read.yaml#steps[0].note note A computes a report twice inside one transaction: count first, then the total. M24 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Replaced at the corresponding logical occurrence; current occurrence scenarios/mysql/02-isolation/phantom-read.yaml#steps[0].note at scenarios/mysql/02-isolation/phantom-read.yaml:12 C00691 base scenarios/mysql/02-isolation/phantom-read.yaml:15 scenarios/mysql/02-isolation/phantom-read.yaml#steps[1].A A SET TRANSACTION ISOLATION LEVEL READ COMMITTED M24 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/phantom-read.yaml#steps[1].A at scenarios/mysql/02-isolation/phantom-read.yaml:15 C00692 base scenarios/mysql/02-isolation/phantom-read.yaml:16 scenarios/mysql/02-isolation/phantom-read.yaml#steps[2].A A BEGIN M24 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/phantom-read.yaml#steps[2].A at scenarios/mysql/02-isolation/phantom-read.yaml:16 C00693 base scenarios/mysql/02-isolation/phantom-read.yaml:18 scenarios/mysql/02-isolation/phantom-read.yaml#steps[3].A A SELECT count(*) AS n FROM orders WHERE amount >= 100 M24 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/phantom-read.yaml#steps[3].A at scenarios/mysql/02-isolation/phantom-read.yaml:18 C00694 base scenarios/mysql/02-isolation/phantom-read.yaml:19 scenarios/mysql/02-isolation/phantom-read.yaml#steps[3].expect[0].n n 2 M24 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/phantom-read.yaml#steps[3].expect[0].n at scenarios/mysql/02-isolation/phantom-read.yaml:19 C00695 base scenarios/mysql/02-isolation/phantom-read.yaml:20 scenarios/mysql/02-isolation/phantom-read.yaml#steps[3].tl tl count(amount ≥ 100) → 2 M24 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/02-isolation/phantom-read.yaml#steps[3].tl at scenarios/mysql/02-isolation/phantom-read.yaml:20 C00696 base scenarios/mysql/02-isolation/phantom-read.yaml:22 scenarios/mysql/02-isolation/phantom-read.yaml#steps[4].note note Between A's two statements, B commits a new order that matches A's WHERE clause. M24 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/02-isolation/phantom-read.yaml#steps[4].note at scenarios/mysql/02-isolation/phantom-read.yaml:22 C00697 base scenarios/mysql/02-isolation/phantom-read.yaml:23 scenarios/mysql/02-isolation/phantom-read.yaml#steps[5].B B INSERT INTO orders VALUES (3, 700) M24 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/phantom-read.yaml#steps[5].B at scenarios/mysql/02-isolation/phantom-read.yaml:23 C00698 base scenarios/mysql/02-isolation/phantom-read.yaml:24 scenarios/mysql/02-isolation/phantom-read.yaml#steps[5].tl tl INSERT order 3 (autocommit) M24 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/02-isolation/phantom-read.yaml#steps[5].tl at scenarios/mysql/02-isolation/phantom-read.yaml:24 C00699 base scenarios/mysql/02-isolation/phantom-read.yaml:26 scenarios/mysql/02-isolation/phantom-read.yaml#steps[6].A A SELECT count(*) AS n, CAST(sum(amount) AS SIGNED) AS total FROM orders WHERE amount >= 100 M24 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/phantom-read.yaml#steps[6].A at scenarios/mysql/02-isolation/phantom-read.yaml:26 C00700 base scenarios/mysql/02-isolation/phantom-read.yaml:27 scenarios/mysql/02-isolation/phantom-read.yaml#steps[6].expect[0].n n 3 M24 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/phantom-read.yaml#steps[6].expect[0].n at scenarios/mysql/02-isolation/phantom-read.yaml:27 C00701 base scenarios/mysql/02-isolation/phantom-read.yaml:27 scenarios/mysql/02-isolation/phantom-read.yaml#steps[6].expect[0].total total 1500 M24 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/phantom-read.yaml#steps[6].expect[0].total at scenarios/mysql/02-isolation/phantom-read.yaml:27 C00702 base scenarios/mysql/02-isolation/phantom-read.yaml:28 scenarios/mysql/02-isolation/phantom-read.yaml#steps[6].comment comment a third row appeared out of nowhere — a phantom M24 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Replaced at the corresponding logical occurrence; current occurrence scenarios/mysql/02-isolation/phantom-read.yaml#steps[6].comment at scenarios/mysql/02-isolation/phantom-read.yaml:28 C00703 base scenarios/mysql/02-isolation/phantom-read.yaml:29 scenarios/mysql/02-isolation/phantom-read.yaml#steps[6].tl tl recount → 3, total 1500 — a phantom M24 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Replaced at the corresponding logical occurrence; current occurrence scenarios/mysql/02-isolation/phantom-read.yaml#steps[6].tl at scenarios/mysql/02-isolation/phantom-read.yaml:29 C00704 base scenarios/mysql/02-isolation/phantom-read.yaml:31 scenarios/mysql/02-isolation/phantom-read.yaml#steps[7].A A COMMIT M24 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/phantom-read.yaml#steps[7].A at scenarios/mysql/02-isolation/phantom-read.yaml:31 C00705 base scenarios/mysql/02-isolation/phantom-read.yaml:32 scenarios/mysql/02-isolation/phantom-read.yaml#steps[8].note note A's report now says '2 orders' in one place and '3 orders, total 1500' in another. M24 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Replaced at the corresponding logical occurrence; current occurrence scenarios/mysql/02-isolation/phantom-read.yaml#steps[8].note at scenarios/mysql/02-isolation/phantom-read.yaml:32 C00706 base scenarios/mysql/02-isolation/read-skew.yaml:1 scenarios/mysql/02-isolation/read-skew.yaml#title title Read skew: one transaction, two rows, an impossible total M25 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/02-isolation/read-skew.yaml#title at scenarios/mysql/02-isolation/read-skew.yaml:1 C00707 base scenarios/mysql/02-isolation/read-skew.yaml:2 scenarios/mysql/02-isolation/read-skew.yaml#claim claim "At READ COMMITTED, a transaction reading two rows around a concurrent transfer observes money that never existed (Adya's G-single, ""read skew""); REPEATABLE READ's transaction-wide snapshot keeps plain SELECTs consistent." M25 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Replaced at the corresponding logical occurrence; current occurrence scenarios/mysql/02-isolation/read-skew.yaml#claim at scenarios/mysql/02-isolation/read-skew.yaml:2 C00708 base scenarios/mysql/02-isolation/read-skew.yaml:6 scenarios/mysql/02-isolation/read-skew.yaml#anomaly anomaly G-single M25 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/read-skew.yaml#anomaly at scenarios/mysql/02-isolation/read-skew.yaml:7 C00709 base scenarios/mysql/02-isolation/read-skew.yaml:7 scenarios/mysql/02-isolation/read-skew.yaml#setup setup "CREATE TABLE accounts (id int PRIMARY KEY, owner varchar(20) NOT NULL, balance int NOT NULL); INSERT INTO accounts VALUES (1, 'alice', 50), (2, 'bob', 50); " M25 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Replaced at the corresponding logical occurrence; current occurrence scenarios/mysql/02-isolation/read-skew.yaml#setup at scenarios/mysql/02-isolation/read-skew.yaml:8 C00710 base scenarios/mysql/02-isolation/read-skew.yaml:10 scenarios/mysql/02-isolation/read-skew.yaml#sessions[0] sessions[0] A M25 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/read-skew.yaml#sessions[0] at scenarios/mysql/02-isolation/read-skew.yaml:11 C00711 base scenarios/mysql/02-isolation/read-skew.yaml:10 scenarios/mysql/02-isolation/read-skew.yaml#sessions[1] sessions[1] B M25 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/read-skew.yaml#sessions[1] at scenarios/mysql/02-isolation/read-skew.yaml:11 C00712 base scenarios/mysql/02-isolation/read-skew.yaml:12 scenarios/mysql/02-isolation/read-skew.yaml#steps[0].note note The invariant: alice + bob = 100 at every moment. A is an auditor summing the accounts row by row; B transfers 25 between them mid-audit. M25 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Replaced at the corresponding logical occurrence; current occurrence scenarios/mysql/02-isolation/read-skew.yaml#steps[0].note at scenarios/mysql/02-isolation/read-skew.yaml:13 C00713 base scenarios/mysql/02-isolation/read-skew.yaml:15 scenarios/mysql/02-isolation/read-skew.yaml#steps[1].A A SET SESSION TRANSACTION ISOLATION LEVEL READ COMMITTED M25 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/read-skew.yaml#steps[1].A at scenarios/mysql/02-isolation/read-skew.yaml:16 C00714 base scenarios/mysql/02-isolation/read-skew.yaml:16 scenarios/mysql/02-isolation/read-skew.yaml#steps[2].A A BEGIN M25 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/read-skew.yaml#steps[2].A at scenarios/mysql/02-isolation/read-skew.yaml:17 C00715 base scenarios/mysql/02-isolation/read-skew.yaml:17 scenarios/mysql/02-isolation/read-skew.yaml#steps[3].A A SELECT balance FROM accounts WHERE owner = 'alice' M25 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/read-skew.yaml#steps[3].A at scenarios/mysql/02-isolation/read-skew.yaml:18 C00716 base scenarios/mysql/02-isolation/read-skew.yaml:18 scenarios/mysql/02-isolation/read-skew.yaml#steps[3].expect[0].balance balance 50 M25 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/read-skew.yaml#steps[3].expect[0].balance at scenarios/mysql/02-isolation/read-skew.yaml:19 C00717 base scenarios/mysql/02-isolation/read-skew.yaml:19 scenarios/mysql/02-isolation/read-skew.yaml#steps[3].tl tl read alice → 50 M25 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/02-isolation/read-skew.yaml#steps[3].tl at scenarios/mysql/02-isolation/read-skew.yaml:20 C00718 base scenarios/mysql/02-isolation/read-skew.yaml:21 scenarios/mysql/02-isolation/read-skew.yaml#steps[4].B B BEGIN M25 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/read-skew.yaml#steps[4].B at scenarios/mysql/02-isolation/read-skew.yaml:22 C00719 base scenarios/mysql/02-isolation/read-skew.yaml:22 scenarios/mysql/02-isolation/read-skew.yaml#steps[5].B B UPDATE accounts SET balance = balance - 25 WHERE owner = 'alice' M25 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/read-skew.yaml#steps[5].B at scenarios/mysql/02-isolation/read-skew.yaml:23 C00720 base scenarios/mysql/02-isolation/read-skew.yaml:23 scenarios/mysql/02-isolation/read-skew.yaml#steps[5].tl tl alice −25 M25 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/02-isolation/read-skew.yaml#steps[5].tl at scenarios/mysql/02-isolation/read-skew.yaml:24 C00721 base scenarios/mysql/02-isolation/read-skew.yaml:24 scenarios/mysql/02-isolation/read-skew.yaml#steps[6].B B UPDATE accounts SET balance = balance + 25 WHERE owner = 'bob' M25 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/read-skew.yaml#steps[6].B at scenarios/mysql/02-isolation/read-skew.yaml:25 C00722 base scenarios/mysql/02-isolation/read-skew.yaml:25 scenarios/mysql/02-isolation/read-skew.yaml#steps[6].tl tl bob +25 M25 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/02-isolation/read-skew.yaml#steps[6].tl at scenarios/mysql/02-isolation/read-skew.yaml:26 C00723 base scenarios/mysql/02-isolation/read-skew.yaml:26 scenarios/mysql/02-isolation/read-skew.yaml#steps[7].B B COMMIT M25 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/read-skew.yaml#steps[7].B at scenarios/mysql/02-isolation/read-skew.yaml:27 C00724 base scenarios/mysql/02-isolation/read-skew.yaml:27 scenarios/mysql/02-isolation/read-skew.yaml#steps[7].comment comment a perfectly correct transfer — atomic, invariant preserved M25 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Replaced at the corresponding logical occurrence; current occurrence scenarios/mysql/02-isolation/read-skew.yaml#steps[7].comment at scenarios/mysql/02-isolation/read-skew.yaml:28 C00725 base scenarios/mysql/02-isolation/read-skew.yaml:28 scenarios/mysql/02-isolation/read-skew.yaml#steps[7].tl tl COMMIT (transfer done) M25 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/02-isolation/read-skew.yaml#steps[7].tl at scenarios/mysql/02-isolation/read-skew.yaml:29 C00726 base scenarios/mysql/02-isolation/read-skew.yaml:30 scenarios/mysql/02-isolation/read-skew.yaml#steps[8].A A SELECT balance FROM accounts WHERE owner = 'bob' M25 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/read-skew.yaml#steps[8].A at scenarios/mysql/02-isolation/read-skew.yaml:31 C00727 base scenarios/mysql/02-isolation/read-skew.yaml:31 scenarios/mysql/02-isolation/read-skew.yaml#steps[8].expect[0].balance balance 75 M25 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/read-skew.yaml#steps[8].expect[0].balance at scenarios/mysql/02-isolation/read-skew.yaml:32 C00728 base scenarios/mysql/02-isolation/read-skew.yaml:32 scenarios/mysql/02-isolation/read-skew.yaml#steps[8].comment comment 50 + 75 = 125. The auditor found 25 that never existed. M25 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/02-isolation/read-skew.yaml#steps[8].comment at scenarios/mysql/02-isolation/read-skew.yaml:33 C00729 base scenarios/mysql/02-isolation/read-skew.yaml:33 scenarios/mysql/02-isolation/read-skew.yaml#steps[8].tl tl read bob → 75 (50 + 75 = 125!) M25 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/02-isolation/read-skew.yaml#steps[8].tl at scenarios/mysql/02-isolation/read-skew.yaml:34 C00730 base scenarios/mysql/02-isolation/read-skew.yaml:34 scenarios/mysql/02-isolation/read-skew.yaml#steps[9].A A COMMIT M25 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/read-skew.yaml#steps[9].A at scenarios/mysql/02-isolation/read-skew.yaml:35 C00731 base scenarios/mysql/02-isolation/read-skew.yaml:36 scenarios/mysql/02-isolation/read-skew.yaml#steps[10].note note Neither row was ever wrong — A read alice BEFORE the transfer and bob AFTER it. REPEATABLE READ pins every plain SELECT to one snapshot: M25 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Replaced at the corresponding logical occurrence; current occurrence scenarios/mysql/02-isolation/read-skew.yaml#steps[10].note at scenarios/mysql/02-isolation/read-skew.yaml:37 C00732 base scenarios/mysql/02-isolation/read-skew.yaml:39 scenarios/mysql/02-isolation/read-skew.yaml#steps[11].A A SET SESSION TRANSACTION ISOLATION LEVEL REPEATABLE READ M25 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/read-skew.yaml#steps[11].A at scenarios/mysql/02-isolation/read-skew.yaml:41 C00733 base scenarios/mysql/02-isolation/read-skew.yaml:40 scenarios/mysql/02-isolation/read-skew.yaml#steps[12].A A BEGIN M25 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/read-skew.yaml#steps[12].A at scenarios/mysql/02-isolation/read-skew.yaml:42 C00734 base scenarios/mysql/02-isolation/read-skew.yaml:41 scenarios/mysql/02-isolation/read-skew.yaml#steps[13].A A SELECT balance FROM accounts WHERE owner = 'alice' M25 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/read-skew.yaml#steps[13].A at scenarios/mysql/02-isolation/read-skew.yaml:43 C00735 base scenarios/mysql/02-isolation/read-skew.yaml:42 scenarios/mysql/02-isolation/read-skew.yaml#steps[13].expect[0].balance balance 25 M25 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/read-skew.yaml#steps[13].expect[0].balance at scenarios/mysql/02-isolation/read-skew.yaml:44 C00736 base scenarios/mysql/02-isolation/read-skew.yaml:44 scenarios/mysql/02-isolation/read-skew.yaml#steps[14].B B BEGIN M25 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/read-skew.yaml#steps[14].B at scenarios/mysql/02-isolation/read-skew.yaml:46 C00737 base scenarios/mysql/02-isolation/read-skew.yaml:45 scenarios/mysql/02-isolation/read-skew.yaml#steps[15].B B UPDATE accounts SET balance = balance - 10 WHERE owner = 'alice' M25 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/read-skew.yaml#steps[15].B at scenarios/mysql/02-isolation/read-skew.yaml:47 C00738 base scenarios/mysql/02-isolation/read-skew.yaml:46 scenarios/mysql/02-isolation/read-skew.yaml#steps[16].B B UPDATE accounts SET balance = balance + 10 WHERE owner = 'bob' M25 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/read-skew.yaml#steps[16].B at scenarios/mysql/02-isolation/read-skew.yaml:48 C00739 base scenarios/mysql/02-isolation/read-skew.yaml:47 scenarios/mysql/02-isolation/read-skew.yaml#steps[17].B B COMMIT M25 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/read-skew.yaml#steps[17].B at scenarios/mysql/02-isolation/read-skew.yaml:49 C00740 base scenarios/mysql/02-isolation/read-skew.yaml:49 scenarios/mysql/02-isolation/read-skew.yaml#steps[18].A A SELECT balance FROM accounts WHERE owner = 'bob' M25 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/read-skew.yaml#steps[18].A at scenarios/mysql/02-isolation/read-skew.yaml:51 C00741 base scenarios/mysql/02-isolation/read-skew.yaml:50 scenarios/mysql/02-isolation/read-skew.yaml#steps[18].expect[0].balance balance 75 M25 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/read-skew.yaml#steps[18].expect[0].balance at scenarios/mysql/02-isolation/read-skew.yaml:52 C00742 base scenarios/mysql/02-isolation/read-skew.yaml:51 scenarios/mysql/02-isolation/read-skew.yaml#steps[18].comment comment 25 + 75 = 100 — one snapshot, one moment in time M25 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Replaced at the corresponding logical occurrence; current occurrence scenarios/mysql/02-isolation/read-skew.yaml#steps[18].comment at scenarios/mysql/02-isolation/read-skew.yaml:53 C00743 base scenarios/mysql/02-isolation/read-skew.yaml:52 scenarios/mysql/02-isolation/read-skew.yaml#steps[19].A A COMMIT M25 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/read-skew.yaml#steps[19].A at scenarios/mysql/02-isolation/read-skew.yaml:54 C00744 base scenarios/mysql/02-isolation/stable-snapshot.yaml:1 scenarios/mysql/02-isolation/stable-snapshot.yaml#title title REPEATABLE READ: one snapshot for the whole transaction M26 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/02-isolation/stable-snapshot.yaml#title at scenarios/mysql/02-isolation/stable-snapshot.yaml:1 C00745 base scenarios/mysql/02-isolation/stable-snapshot.yaml:2 scenarios/mysql/02-isolation/stable-snapshot.yaml#claim claim At REPEATABLE READ — MySQL's default — plain SELECTs use a single snapshot for the entire transaction: no non-repeatable reads and no phantoms. M26 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Replaced at the corresponding logical occurrence; current occurrence scenarios/mysql/02-isolation/stable-snapshot.yaml#claim at scenarios/mysql/02-isolation/stable-snapshot.yaml:2 C00746 base scenarios/mysql/02-isolation/stable-snapshot.yaml:5 scenarios/mysql/02-isolation/stable-snapshot.yaml#anomaly anomaly P2 M26 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/stable-snapshot.yaml#anomaly at scenarios/mysql/02-isolation/stable-snapshot.yaml:6 C00747 base scenarios/mysql/02-isolation/stable-snapshot.yaml:6 scenarios/mysql/02-isolation/stable-snapshot.yaml#setup setup "CREATE TABLE accounts (id int PRIMARY KEY, owner varchar(20) NOT NULL, balance int NOT NULL); INSERT INTO accounts VALUES (1, 'alice', 100), (2, 'bob', 50); " M26 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Replaced at the corresponding logical occurrence; current occurrence scenarios/mysql/02-isolation/stable-snapshot.yaml#setup at scenarios/mysql/02-isolation/stable-snapshot.yaml:8 C00748 base scenarios/mysql/02-isolation/stable-snapshot.yaml:9 scenarios/mysql/02-isolation/stable-snapshot.yaml#sessions[0] sessions[0] A M26 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/stable-snapshot.yaml#sessions[0] at scenarios/mysql/02-isolation/stable-snapshot.yaml:11 C00749 base scenarios/mysql/02-isolation/stable-snapshot.yaml:9 scenarios/mysql/02-isolation/stable-snapshot.yaml#sessions[1] sessions[1] B M26 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/stable-snapshot.yaml#sessions[1] at scenarios/mysql/02-isolation/stable-snapshot.yaml:11 C00750 base scenarios/mysql/02-isolation/stable-snapshot.yaml:11 scenarios/mysql/02-isolation/stable-snapshot.yaml#steps[0].A A BEGIN M26 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/stable-snapshot.yaml#steps[1].A at scenarios/mysql/02-isolation/stable-snapshot.yaml:14 C00751 base scenarios/mysql/02-isolation/stable-snapshot.yaml:13 scenarios/mysql/02-isolation/stable-snapshot.yaml#steps[1].note note The snapshot is taken by the FIRST query, not by BEGIN. M26 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Replaced at the corresponding logical occurrence; current occurrence scenarios/mysql/02-isolation/stable-snapshot.yaml#steps[3].note at scenarios/mysql/02-isolation/stable-snapshot.yaml:17 C00752 base scenarios/mysql/02-isolation/stable-snapshot.yaml:14 scenarios/mysql/02-isolation/stable-snapshot.yaml#steps[2].A A SELECT id, balance FROM accounts ORDER BY id M26 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/stable-snapshot.yaml#steps[4].A at scenarios/mysql/02-isolation/stable-snapshot.yaml:18 C00753 base scenarios/mysql/02-isolation/stable-snapshot.yaml:16 scenarios/mysql/02-isolation/stable-snapshot.yaml#steps[2].tl tl SELECT → 100, 50 (snapshot taken) M26 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Replaced at the corresponding logical occurrence; current occurrence scenarios/mysql/02-isolation/stable-snapshot.yaml#steps[4].tl at scenarios/mysql/02-isolation/stable-snapshot.yaml:20 C00754 base scenarios/mysql/02-isolation/stable-snapshot.yaml:18 scenarios/mysql/02-isolation/stable-snapshot.yaml#steps[3].note note B changes an existing row AND inserts a new one — both committed instantly. M26 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Replaced at the corresponding logical occurrence; current occurrence scenarios/mysql/02-isolation/stable-snapshot.yaml#steps[5].note at scenarios/mysql/02-isolation/stable-snapshot.yaml:22 C00755 base scenarios/mysql/02-isolation/stable-snapshot.yaml:19 scenarios/mysql/02-isolation/stable-snapshot.yaml#steps[4].B B UPDATE accounts SET balance = 999 WHERE id = 1 M26 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/stable-snapshot.yaml#steps[6].B at scenarios/mysql/02-isolation/stable-snapshot.yaml:23 C00756 base scenarios/mysql/02-isolation/stable-snapshot.yaml:20 scenarios/mysql/02-isolation/stable-snapshot.yaml#steps[4].tl tl UPDATE id1 = 999 (committed) M26 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/02-isolation/stable-snapshot.yaml#steps[6].tl at scenarios/mysql/02-isolation/stable-snapshot.yaml:24 C00757 base scenarios/mysql/02-isolation/stable-snapshot.yaml:21 scenarios/mysql/02-isolation/stable-snapshot.yaml#steps[5].B B INSERT INTO accounts VALUES (3, 'carol', 300) M26 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/stable-snapshot.yaml#steps[7].B at scenarios/mysql/02-isolation/stable-snapshot.yaml:25 C00758 base scenarios/mysql/02-isolation/stable-snapshot.yaml:22 scenarios/mysql/02-isolation/stable-snapshot.yaml#steps[5].tl tl INSERT carol (committed) M26 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/02-isolation/stable-snapshot.yaml#steps[7].tl at scenarios/mysql/02-isolation/stable-snapshot.yaml:26 C00759 base scenarios/mysql/02-isolation/stable-snapshot.yaml:24 scenarios/mysql/02-isolation/stable-snapshot.yaml#steps[6].A A SELECT id, balance FROM accounts ORDER BY id M26 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/stable-snapshot.yaml#steps[8].A at scenarios/mysql/02-isolation/stable-snapshot.yaml:28 C00760 base scenarios/mysql/02-isolation/stable-snapshot.yaml:26 scenarios/mysql/02-isolation/stable-snapshot.yaml#steps[6].expect[0].id id 1 M26 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/stable-snapshot.yaml#steps[8].expect[0].id at scenarios/mysql/02-isolation/stable-snapshot.yaml:30 C00761 base scenarios/mysql/02-isolation/stable-snapshot.yaml:26 scenarios/mysql/02-isolation/stable-snapshot.yaml#steps[6].expect[0].balance balance 100 M26 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Replaced at the corresponding logical occurrence; current occurrence scenarios/mysql/02-isolation/stable-snapshot.yaml#steps[8].expect[0].balance at scenarios/mysql/02-isolation/stable-snapshot.yaml:30 C00762 base scenarios/mysql/02-isolation/stable-snapshot.yaml:27 scenarios/mysql/02-isolation/stable-snapshot.yaml#steps[6].expect[1].id id 2 M26 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/stable-snapshot.yaml#steps[8].expect[1].id at scenarios/mysql/02-isolation/stable-snapshot.yaml:31 C00763 base scenarios/mysql/02-isolation/stable-snapshot.yaml:27 scenarios/mysql/02-isolation/stable-snapshot.yaml#steps[6].expect[1].balance balance 50 M26 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/stable-snapshot.yaml#steps[8].expect[1].balance at scenarios/mysql/02-isolation/stable-snapshot.yaml:31 C00764 base scenarios/mysql/02-isolation/stable-snapshot.yaml:28 scenarios/mysql/02-isolation/stable-snapshot.yaml#steps[6].comment comment not 999 — no non-repeatable read; and no carol — no phantom M26 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Replaced at the corresponding logical occurrence; current occurrence scenarios/mysql/02-isolation/stable-snapshot.yaml#steps[8].comment at scenarios/mysql/02-isolation/stable-snapshot.yaml:32 C00765 base scenarios/mysql/02-isolation/stable-snapshot.yaml:29 scenarios/mysql/02-isolation/stable-snapshot.yaml#steps[6].tl tl SELECT → 100, 50 — no 999, no carol M26 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Replaced at the corresponding logical occurrence; current occurrence scenarios/mysql/02-isolation/stable-snapshot.yaml#steps[8].tl at scenarios/mysql/02-isolation/stable-snapshot.yaml:33 C00766 base scenarios/mysql/02-isolation/stable-snapshot.yaml:31 scenarios/mysql/02-isolation/stable-snapshot.yaml#steps[7].A A COMMIT M26 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/stable-snapshot.yaml#steps[11].A at scenarios/mysql/02-isolation/stable-snapshot.yaml:40 C00767 base scenarios/mysql/02-isolation/stable-snapshot.yaml:32 scenarios/mysql/02-isolation/stable-snapshot.yaml#steps[7].tl tl COMMIT M26 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/02-isolation/stable-snapshot.yaml#steps[11].tl at scenarios/mysql/02-isolation/stable-snapshot.yaml:41 C00768 base scenarios/mysql/02-isolation/stable-snapshot.yaml:34 scenarios/mysql/02-isolation/stable-snapshot.yaml#steps[8].note note Only a NEW transaction gets a new snapshot. M26 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Replaced at the corresponding logical occurrence; current occurrence scenarios/mysql/02-isolation/stable-snapshot.yaml#steps[12].note at scenarios/mysql/02-isolation/stable-snapshot.yaml:43 C00769 base scenarios/mysql/02-isolation/stable-snapshot.yaml:35 scenarios/mysql/02-isolation/stable-snapshot.yaml#steps[9].A A SELECT id, balance FROM accounts ORDER BY id M26 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/stable-snapshot.yaml#steps[13].A at scenarios/mysql/02-isolation/stable-snapshot.yaml:44 C00770 base scenarios/mysql/02-isolation/stable-snapshot.yaml:36 scenarios/mysql/02-isolation/stable-snapshot.yaml#steps[9].expect[0].balance balance 999 M26 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/stable-snapshot.yaml#steps[13].expect[0].balance at scenarios/mysql/02-isolation/stable-snapshot.yaml:45 C00771 base scenarios/mysql/02-isolation/stable-snapshot.yaml:37 scenarios/mysql/02-isolation/stable-snapshot.yaml#steps[9].tl tl SELECT → 999 + carol (new snapshot) M26 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/02-isolation/stable-snapshot.yaml#steps[13].tl at scenarios/mysql/02-isolation/stable-snapshot.yaml:46 C00772 base scenarios/mysql/02-isolation/update-recheck.yaml:1 scenarios/mysql/02-isolation/update-recheck.yaml#title title READ COMMITTED re-checks WHERE after waiting M27 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/02-isolation/update-recheck.yaml#title at scenarios/mysql/02-isolation/update-recheck.yaml:1 C00773 base scenarios/mysql/02-isolation/update-recheck.yaml:2 scenarios/mysql/02-isolation/update-recheck.yaml#claim claim An UPDATE at READ COMMITTED that waited for a lock re-evaluates its WHERE clause against the new row version — rows that no longer match are silently skipped. M27 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Replaced at the corresponding logical occurrence; current occurrence scenarios/mysql/02-isolation/update-recheck.yaml#claim at scenarios/mysql/02-isolation/update-recheck.yaml:2 C00774 base scenarios/mysql/02-isolation/update-recheck.yaml:6 scenarios/mysql/02-isolation/update-recheck.yaml#setup setup "CREATE TABLE items (id int PRIMARY KEY, value int NOT NULL); INSERT INTO items VALUES (1, 10), (2, 30); " M27 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Replaced at the corresponding logical occurrence; current occurrence scenarios/mysql/02-isolation/update-recheck.yaml#setup at scenarios/mysql/02-isolation/update-recheck.yaml:6 C00775 base scenarios/mysql/02-isolation/update-recheck.yaml:9 scenarios/mysql/02-isolation/update-recheck.yaml#sessions[0] sessions[0] A M27 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/update-recheck.yaml#sessions[0] at scenarios/mysql/02-isolation/update-recheck.yaml:9 C00776 base scenarios/mysql/02-isolation/update-recheck.yaml:9 scenarios/mysql/02-isolation/update-recheck.yaml#sessions[1] sessions[1] B M27 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/update-recheck.yaml#sessions[1] at scenarios/mysql/02-isolation/update-recheck.yaml:9 C00777 base scenarios/mysql/02-isolation/update-recheck.yaml:11 scenarios/mysql/02-isolation/update-recheck.yaml#steps[0].A A BEGIN M27 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/update-recheck.yaml#steps[0].A at scenarios/mysql/02-isolation/update-recheck.yaml:11 C00778 base scenarios/mysql/02-isolation/update-recheck.yaml:12 scenarios/mysql/02-isolation/update-recheck.yaml#steps[1].A A UPDATE items SET value = value * 2 WHERE id = 1 M27 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/update-recheck.yaml#steps[1].A at scenarios/mysql/02-isolation/update-recheck.yaml:12 C00779 base scenarios/mysql/02-isolation/update-recheck.yaml:13 scenarios/mysql/02-isolation/update-recheck.yaml#steps[1].comment comment row 1: 10 → 20, uncommitted M27 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/02-isolation/update-recheck.yaml#steps[1].comment at scenarios/mysql/02-isolation/update-recheck.yaml:13 C00780 base scenarios/mysql/02-isolation/update-recheck.yaml:14 scenarios/mysql/02-isolation/update-recheck.yaml#steps[1].tl tl UPDATE row1 → 20 (uncommitted) M27 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/02-isolation/update-recheck.yaml#steps[1].tl at scenarios/mysql/02-isolation/update-recheck.yaml:14 C00781 base scenarios/mysql/02-isolation/update-recheck.yaml:16 scenarios/mysql/02-isolation/update-recheck.yaml#steps[2].note note B targets WHERE value = 10. The latest committed version of row 1 still qualifies — but it's locked by A, so B waits. M27 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Replaced at the corresponding logical occurrence; current occurrence scenarios/mysql/02-isolation/update-recheck.yaml#steps[2].note at scenarios/mysql/02-isolation/update-recheck.yaml:16 C00782 base scenarios/mysql/02-isolation/update-recheck.yaml:19 scenarios/mysql/02-isolation/update-recheck.yaml#steps[3].B B SET TRANSACTION ISOLATION LEVEL READ COMMITTED M27 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=READ COMMITTED, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/update-recheck.yaml#steps[3].B at scenarios/mysql/02-isolation/update-recheck.yaml:19 C00783 base scenarios/mysql/02-isolation/update-recheck.yaml:20 scenarios/mysql/02-isolation/update-recheck.yaml#steps[4].B B BEGIN M27 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=READ COMMITTED, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/update-recheck.yaml#steps[4].B at scenarios/mysql/02-isolation/update-recheck.yaml:20 C00784 base scenarios/mysql/02-isolation/update-recheck.yaml:21 scenarios/mysql/02-isolation/update-recheck.yaml#steps[5].B B UPDATE items SET value = 99 WHERE value = 10 M27 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/update-recheck.yaml#steps[5].B at scenarios/mysql/02-isolation/update-recheck.yaml:21 C00785 base scenarios/mysql/02-isolation/update-recheck.yaml:22 scenarios/mysql/02-isolation/update-recheck.yaml#steps[5].blocks blocks p1 M27 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/update-recheck.yaml#steps[5].blocks at scenarios/mysql/02-isolation/update-recheck.yaml:22 C00786 base scenarios/mysql/02-isolation/update-recheck.yaml:23 scenarios/mysql/02-isolation/update-recheck.yaml#steps[5].tl tl UPDATE WHERE value = 10 M27 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/02-isolation/update-recheck.yaml#steps[5].tl at scenarios/mysql/02-isolation/update-recheck.yaml:23 C00787 base scenarios/mysql/02-isolation/update-recheck.yaml:25 scenarios/mysql/02-isolation/update-recheck.yaml#steps[6].note note A commits. B wakes up and re-checks the row it waited for — against the NEW version, where value is 20. M27 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Replaced at the corresponding logical occurrence; current occurrence scenarios/mysql/02-isolation/update-recheck.yaml#steps[6].note at scenarios/mysql/02-isolation/update-recheck.yaml:25 C00788 base scenarios/mysql/02-isolation/update-recheck.yaml:28 scenarios/mysql/02-isolation/update-recheck.yaml#steps[7].A A COMMIT M27 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/update-recheck.yaml#steps[7].A at scenarios/mysql/02-isolation/update-recheck.yaml:28 C00789 base scenarios/mysql/02-isolation/update-recheck.yaml:29 scenarios/mysql/02-isolation/update-recheck.yaml#steps[7].tl tl COMMIT — row1 is now 20 M27 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Replaced at the corresponding logical occurrence; current occurrence scenarios/mysql/02-isolation/update-recheck.yaml#steps[7].tl at scenarios/mysql/02-isolation/update-recheck.yaml:29 C00790 base scenarios/mysql/02-isolation/update-recheck.yaml:31 scenarios/mysql/02-isolation/update-recheck.yaml#steps[8].success success p1 M27 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/update-recheck.yaml#steps[8].success at scenarios/mysql/02-isolation/update-recheck.yaml:31 C00791 base scenarios/mysql/02-isolation/update-recheck.yaml:32 scenarios/mysql/02-isolation/update-recheck.yaml#steps[8].affected affected 0 M27 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/update-recheck.yaml#steps[8].affected at scenarios/mysql/02-isolation/update-recheck.yaml:32 C00792 base scenarios/mysql/02-isolation/update-recheck.yaml:33 scenarios/mysql/02-isolation/update-recheck.yaml#steps[9].note note 0 rows affected — the row slipped away. M27 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Replaced at the corresponding logical occurrence; current occurrence scenarios/mysql/02-isolation/update-recheck.yaml#steps[9].note at scenarios/mysql/02-isolation/update-recheck.yaml:33 C00793 base scenarios/mysql/02-isolation/update-recheck.yaml:34 scenarios/mysql/02-isolation/update-recheck.yaml#steps[10].B B COMMIT M27 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/update-recheck.yaml#steps[10].B at scenarios/mysql/02-isolation/update-recheck.yaml:34 C00794 base scenarios/mysql/02-isolation/update-recheck.yaml:36 scenarios/mysql/02-isolation/update-recheck.yaml#steps[11].B B SELECT id, value FROM items ORDER BY id M27 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/update-recheck.yaml#steps[11].B at scenarios/mysql/02-isolation/update-recheck.yaml:36 C00795 base scenarios/mysql/02-isolation/update-recheck.yaml:38 scenarios/mysql/02-isolation/update-recheck.yaml#steps[11].expect[0].id id 1 M27 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/update-recheck.yaml#steps[11].expect[0].id at scenarios/mysql/02-isolation/update-recheck.yaml:38 C00796 base scenarios/mysql/02-isolation/update-recheck.yaml:38 scenarios/mysql/02-isolation/update-recheck.yaml#steps[11].expect[0].value value 20 M27 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/update-recheck.yaml#steps[11].expect[0].value at scenarios/mysql/02-isolation/update-recheck.yaml:38 C00797 base scenarios/mysql/02-isolation/update-recheck.yaml:39 scenarios/mysql/02-isolation/update-recheck.yaml#steps[11].expect[1].id id 2 M27 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/update-recheck.yaml#steps[11].expect[1].id at scenarios/mysql/02-isolation/update-recheck.yaml:39 C00798 base scenarios/mysql/02-isolation/update-recheck.yaml:39 scenarios/mysql/02-isolation/update-recheck.yaml#steps[11].expect[1].value value 30 M27 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/update-recheck.yaml#steps[11].expect[1].value at scenarios/mysql/02-isolation/update-recheck.yaml:39 C00799 base scenarios/mysql/02-isolation/write-predicate-skew.yaml:1 scenarios/mysql/02-isolation/write-predicate-skew.yaml#title title Your DELETE and your SELECT live in different worlds M28 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/02-isolation/write-predicate-skew.yaml#title at scenarios/mysql/02-isolation/write-predicate-skew.yaml:1 C00800 base scenarios/mysql/02-isolation/write-predicate-skew.yaml:2 scenarios/mysql/02-isolation/write-predicate-skew.yaml#claim claim "Under REPEATABLE READ a write's WHERE clause is evaluated against the CURRENT committed data while SELECTs keep showing the snapshot — so a transaction can ""delete every row matching X"", delete nothing, and still see rows matching X (Hermitage's G-single write-predicate anomaly)." M28 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Replaced at the corresponding logical occurrence; current occurrence scenarios/mysql/02-isolation/write-predicate-skew.yaml#claim at scenarios/mysql/02-isolation/write-predicate-skew.yaml:2 C00801 base scenarios/mysql/02-isolation/write-predicate-skew.yaml:7 scenarios/mysql/02-isolation/write-predicate-skew.yaml#setup setup "CREATE TABLE accounts (id int PRIMARY KEY, owner varchar(20) NOT NULL, balance int NOT NULL); INSERT INTO accounts VALUES (1, 'alice', 10), (2, 'bob', 20); " M28 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Replaced at the corresponding logical occurrence; current occurrence scenarios/mysql/02-isolation/write-predicate-skew.yaml#setup at scenarios/mysql/02-isolation/write-predicate-skew.yaml:6 C00802 base scenarios/mysql/02-isolation/write-predicate-skew.yaml:10 scenarios/mysql/02-isolation/write-predicate-skew.yaml#sessions[0] sessions[0] A M28 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/write-predicate-skew.yaml#sessions[0] at scenarios/mysql/02-isolation/write-predicate-skew.yaml:9 C00803 base scenarios/mysql/02-isolation/write-predicate-skew.yaml:10 scenarios/mysql/02-isolation/write-predicate-skew.yaml#sessions[1] sessions[1] B M28 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/write-predicate-skew.yaml#sessions[1] at scenarios/mysql/02-isolation/write-predicate-skew.yaml:9 C00804 base scenarios/mysql/02-isolation/write-predicate-skew.yaml:12 scenarios/mysql/02-isolation/write-predicate-skew.yaml#steps[0].note note A opens a snapshot. B then reshuffles every balance and commits. M28 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/02-isolation/write-predicate-skew.yaml#steps[1].note at scenarios/mysql/02-isolation/write-predicate-skew.yaml:12 C00805 base scenarios/mysql/02-isolation/write-predicate-skew.yaml:13 scenarios/mysql/02-isolation/write-predicate-skew.yaml#steps[1].A A BEGIN M28 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/write-predicate-skew.yaml#steps[2].A at scenarios/mysql/02-isolation/write-predicate-skew.yaml:13 C00806 base scenarios/mysql/02-isolation/write-predicate-skew.yaml:14 scenarios/mysql/02-isolation/write-predicate-skew.yaml#steps[2].A A SELECT id, balance FROM accounts ORDER BY id M28 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/write-predicate-skew.yaml#steps[3].A at scenarios/mysql/02-isolation/write-predicate-skew.yaml:14 C00807 base scenarios/mysql/02-isolation/write-predicate-skew.yaml:15 scenarios/mysql/02-isolation/write-predicate-skew.yaml#steps[2].expect[0].id id 1 M28 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/write-predicate-skew.yaml#steps[3].expect[0].id at scenarios/mysql/02-isolation/write-predicate-skew.yaml:15 C00808 base scenarios/mysql/02-isolation/write-predicate-skew.yaml:15 scenarios/mysql/02-isolation/write-predicate-skew.yaml#steps[2].expect[0].balance balance 10 M28 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/write-predicate-skew.yaml#steps[3].expect[0].balance at scenarios/mysql/02-isolation/write-predicate-skew.yaml:15 C00809 base scenarios/mysql/02-isolation/write-predicate-skew.yaml:15 scenarios/mysql/02-isolation/write-predicate-skew.yaml#steps[2].expect[1].id id 2 M28 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/write-predicate-skew.yaml#steps[3].expect[1].id at scenarios/mysql/02-isolation/write-predicate-skew.yaml:15 C00810 base scenarios/mysql/02-isolation/write-predicate-skew.yaml:15 scenarios/mysql/02-isolation/write-predicate-skew.yaml#steps[2].expect[1].balance balance 20 M28 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/write-predicate-skew.yaml#steps[3].expect[1].balance at scenarios/mysql/02-isolation/write-predicate-skew.yaml:15 C00811 base scenarios/mysql/02-isolation/write-predicate-skew.yaml:16 scenarios/mysql/02-isolation/write-predicate-skew.yaml#steps[2].comment comment snapshot taken M28 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/02-isolation/write-predicate-skew.yaml#steps[3].comment at scenarios/mysql/02-isolation/write-predicate-skew.yaml:16 C00812 base scenarios/mysql/02-isolation/write-predicate-skew.yaml:17 scenarios/mysql/02-isolation/write-predicate-skew.yaml#steps[2].tl tl SELECT → 10, 20 (snapshot) M28 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/02-isolation/write-predicate-skew.yaml#steps[3].tl at scenarios/mysql/02-isolation/write-predicate-skew.yaml:17 C00813 base scenarios/mysql/02-isolation/write-predicate-skew.yaml:19 scenarios/mysql/02-isolation/write-predicate-skew.yaml#steps[3].B B BEGIN M28 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/write-predicate-skew.yaml#steps[4].B at scenarios/mysql/02-isolation/write-predicate-skew.yaml:19 C00814 base scenarios/mysql/02-isolation/write-predicate-skew.yaml:20 scenarios/mysql/02-isolation/write-predicate-skew.yaml#steps[4].B B UPDATE accounts SET balance = balance + 5 M28 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/write-predicate-skew.yaml#steps[5].B at scenarios/mysql/02-isolation/write-predicate-skew.yaml:20 C00815 base scenarios/mysql/02-isolation/write-predicate-skew.yaml:21 scenarios/mysql/02-isolation/write-predicate-skew.yaml#steps[4].tl tl +5 to every balance M28 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/02-isolation/write-predicate-skew.yaml#steps[5].tl at scenarios/mysql/02-isolation/write-predicate-skew.yaml:21 C00816 base scenarios/mysql/02-isolation/write-predicate-skew.yaml:22 scenarios/mysql/02-isolation/write-predicate-skew.yaml#steps[5].B B COMMIT M28 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/write-predicate-skew.yaml#steps[6].B at scenarios/mysql/02-isolation/write-predicate-skew.yaml:22 C00817 base scenarios/mysql/02-isolation/write-predicate-skew.yaml:23 scenarios/mysql/02-isolation/write-predicate-skew.yaml#steps[5].comment comment current data is now 15 and 25 M28 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/02-isolation/write-predicate-skew.yaml#steps[6].comment at scenarios/mysql/02-isolation/write-predicate-skew.yaml:23 C00818 base scenarios/mysql/02-isolation/write-predicate-skew.yaml:24 scenarios/mysql/02-isolation/write-predicate-skew.yaml#steps[5].tl tl COMMIT (now 15, 25) M28 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/02-isolation/write-predicate-skew.yaml#steps[6].tl at scenarios/mysql/02-isolation/write-predicate-skew.yaml:24 C00819 base scenarios/mysql/02-isolation/write-predicate-skew.yaml:26 scenarios/mysql/02-isolation/write-predicate-skew.yaml#steps[6].note note A closes every account with balance 20 — its snapshot says that's bob. But the DELETE is a current read: it scans the committed 15 and 25, finds nothing, and deletes nothing. M28 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Replaced at the corresponding logical occurrence; current occurrence scenarios/mysql/02-isolation/write-predicate-skew.yaml#steps[7].note at scenarios/mysql/02-isolation/write-predicate-skew.yaml:26 C00820 base scenarios/mysql/02-isolation/write-predicate-skew.yaml:30 scenarios/mysql/02-isolation/write-predicate-skew.yaml#steps[7].A A DELETE FROM accounts WHERE balance = 20 M28 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/write-predicate-skew.yaml#steps[8].A at scenarios/mysql/02-isolation/write-predicate-skew.yaml:30 C00821 base scenarios/mysql/02-isolation/write-predicate-skew.yaml:31 scenarios/mysql/02-isolation/write-predicate-skew.yaml#steps[7].affected affected 0 M28 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/write-predicate-skew.yaml#steps[8].affected at scenarios/mysql/02-isolation/write-predicate-skew.yaml:31 C00822 base scenarios/mysql/02-isolation/write-predicate-skew.yaml:32 scenarios/mysql/02-isolation/write-predicate-skew.yaml#steps[7].tl tl DELETE balance = 20 → 0 rows M28 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/02-isolation/write-predicate-skew.yaml#steps[8].tl at scenarios/mysql/02-isolation/write-predicate-skew.yaml:32 C00823 base scenarios/mysql/02-isolation/write-predicate-skew.yaml:34 scenarios/mysql/02-isolation/write-predicate-skew.yaml#steps[8].A A SELECT id, balance FROM accounts WHERE balance = 20 ORDER BY id M28 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/write-predicate-skew.yaml#steps[9].A at scenarios/mysql/02-isolation/write-predicate-skew.yaml:34 C00824 base scenarios/mysql/02-isolation/write-predicate-skew.yaml:35 scenarios/mysql/02-isolation/write-predicate-skew.yaml#steps[8].expect[0].id id 2 M28 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/write-predicate-skew.yaml#steps[9].expect[0].id at scenarios/mysql/02-isolation/write-predicate-skew.yaml:35 C00825 base scenarios/mysql/02-isolation/write-predicate-skew.yaml:35 scenarios/mysql/02-isolation/write-predicate-skew.yaml#steps[8].expect[0].balance balance 20 M28 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/write-predicate-skew.yaml#steps[9].expect[0].balance at scenarios/mysql/02-isolation/write-predicate-skew.yaml:35 C00826 base scenarios/mysql/02-isolation/write-predicate-skew.yaml:36 scenarios/mysql/02-isolation/write-predicate-skew.yaml#steps[8].comment comment …yet A still SEES a row with balance 20. Deleted: no such rows. Visible: one. M28 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/02-isolation/write-predicate-skew.yaml#steps[9].comment at scenarios/mysql/02-isolation/write-predicate-skew.yaml:36 C00827 base scenarios/mysql/02-isolation/write-predicate-skew.yaml:37 scenarios/mysql/02-isolation/write-predicate-skew.yaml#steps[8].tl tl SELECT balance = 20 → still sees bob M28 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/02-isolation/write-predicate-skew.yaml#steps[9].tl at scenarios/mysql/02-isolation/write-predicate-skew.yaml:37 C00828 base scenarios/mysql/02-isolation/write-predicate-skew.yaml:38 scenarios/mysql/02-isolation/write-predicate-skew.yaml#steps[9].A A COMMIT M28 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/write-predicate-skew.yaml#steps[10].A at scenarios/mysql/02-isolation/write-predicate-skew.yaml:38 C00829 base scenarios/mysql/02-isolation/write-predicate-skew.yaml:40 scenarios/mysql/02-isolation/write-predicate-skew.yaml#steps[10].note note A's writes ran in one world, its reads in another. PostgreSQL's REPEATABLE READ aborts the DELETE with a serialization failure instead; on MySQL the cure is a locking read (FOR UPDATE) or SERIALIZABLE. M28 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Replaced at the corresponding logical occurrence; current occurrence scenarios/mysql/02-isolation/write-predicate-skew.yaml#steps[11].note at scenarios/mysql/02-isolation/write-predicate-skew.yaml:40 C00830 base scenarios/mysql/02-isolation/write-skew-rr.yaml:1 scenarios/mysql/02-isolation/write-skew-rr.yaml#title title Write skew: REPEATABLE READ is not enough M29 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/02-isolation/write-skew-rr.yaml#title at scenarios/mysql/02-isolation/write-skew-rr.yaml:1 C00831 base scenarios/mysql/02-isolation/write-skew-rr.yaml:2 scenarios/mysql/02-isolation/write-skew-rr.yaml#claim claim Two REPEATABLE READ transactions can each validate an invariant against their snapshots, write to different rows, and both commit — leaving the invariant broken. This is write skew. M29 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Replaced at the corresponding logical occurrence; current occurrence scenarios/mysql/02-isolation/write-skew-rr.yaml#claim at scenarios/mysql/02-isolation/write-skew-rr.yaml:2 C00832 base scenarios/mysql/02-isolation/write-skew-rr.yaml:6 scenarios/mysql/02-isolation/write-skew-rr.yaml#anomaly anomaly G2-item M29 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/write-skew-rr.yaml#anomaly at scenarios/mysql/02-isolation/write-skew-rr.yaml:6 C00833 base scenarios/mysql/02-isolation/write-skew-rr.yaml:7 scenarios/mysql/02-isolation/write-skew-rr.yaml#setup setup "CREATE TABLE doctors (name varchar(20) PRIMARY KEY, on_call boolean NOT NULL); INSERT INTO doctors VALUES ('alice', true), ('bob', true); " M29 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Replaced at the corresponding logical occurrence; current occurrence scenarios/mysql/02-isolation/write-skew-rr.yaml#setup at scenarios/mysql/02-isolation/write-skew-rr.yaml:8 C00834 base scenarios/mysql/02-isolation/write-skew-rr.yaml:10 scenarios/mysql/02-isolation/write-skew-rr.yaml#sessions[0] sessions[0] A M29 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/write-skew-rr.yaml#sessions[0] at scenarios/mysql/02-isolation/write-skew-rr.yaml:11 C00835 base scenarios/mysql/02-isolation/write-skew-rr.yaml:10 scenarios/mysql/02-isolation/write-skew-rr.yaml#sessions[1] sessions[1] B M29 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/write-skew-rr.yaml#sessions[1] at scenarios/mysql/02-isolation/write-skew-rr.yaml:11 C00836 base scenarios/mysql/02-isolation/write-skew-rr.yaml:12 scenarios/mysql/02-isolation/write-skew-rr.yaml#steps[0].note note Hospital rule: at least one doctor must stay on call. Alice and Bob both want the night off. M29 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/02-isolation/write-skew-rr.yaml#steps[2].note at scenarios/mysql/02-isolation/write-skew-rr.yaml:15 C00837 base scenarios/mysql/02-isolation/write-skew-rr.yaml:15 scenarios/mysql/02-isolation/write-skew-rr.yaml#steps[1].A A BEGIN M29 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/write-skew-rr.yaml#steps[3].A at scenarios/mysql/02-isolation/write-skew-rr.yaml:18 C00838 base scenarios/mysql/02-isolation/write-skew-rr.yaml:16 scenarios/mysql/02-isolation/write-skew-rr.yaml#steps[2].B B BEGIN M29 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/write-skew-rr.yaml#steps[4].B at scenarios/mysql/02-isolation/write-skew-rr.yaml:19 C00839 base scenarios/mysql/02-isolation/write-skew-rr.yaml:18 scenarios/mysql/02-isolation/write-skew-rr.yaml#steps[3].A A SELECT count(*) AS on_call FROM doctors WHERE on_call M29 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/write-skew-rr.yaml#steps[5].A at scenarios/mysql/02-isolation/write-skew-rr.yaml:21 C00840 base scenarios/mysql/02-isolation/write-skew-rr.yaml:19 scenarios/mysql/02-isolation/write-skew-rr.yaml#steps[3].expect[0].on_call on_call 2 M29 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/write-skew-rr.yaml#steps[5].expect[0].on_call at scenarios/mysql/02-isolation/write-skew-rr.yaml:22 C00841 base scenarios/mysql/02-isolation/write-skew-rr.yaml:20 scenarios/mysql/02-isolation/write-skew-rr.yaml#steps[3].comment comment """two of us — safe for me to leave""" M29 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Replaced at the corresponding logical occurrence; current occurrence scenarios/mysql/02-isolation/write-skew-rr.yaml#steps[5].comment at scenarios/mysql/02-isolation/write-skew-rr.yaml:23 C00842 base scenarios/mysql/02-isolation/write-skew-rr.yaml:21 scenarios/mysql/02-isolation/write-skew-rr.yaml#steps[3].tl tl on-call count → 2 M29 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/02-isolation/write-skew-rr.yaml#steps[5].tl at scenarios/mysql/02-isolation/write-skew-rr.yaml:24 C00843 base scenarios/mysql/02-isolation/write-skew-rr.yaml:23 scenarios/mysql/02-isolation/write-skew-rr.yaml#steps[4].B B SELECT count(*) AS on_call FROM doctors WHERE on_call M29 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/write-skew-rr.yaml#steps[6].B at scenarios/mysql/02-isolation/write-skew-rr.yaml:26 C00844 base scenarios/mysql/02-isolation/write-skew-rr.yaml:24 scenarios/mysql/02-isolation/write-skew-rr.yaml#steps[4].expect[0].on_call on_call 2 M29 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/write-skew-rr.yaml#steps[6].expect[0].on_call at scenarios/mysql/02-isolation/write-skew-rr.yaml:27 C00845 base scenarios/mysql/02-isolation/write-skew-rr.yaml:25 scenarios/mysql/02-isolation/write-skew-rr.yaml#steps[4].comment comment """two of us — safe for me to leave""" M29 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Replaced at the corresponding logical occurrence; current occurrence scenarios/mysql/02-isolation/write-skew-rr.yaml#steps[6].comment at scenarios/mysql/02-isolation/write-skew-rr.yaml:28 C00846 base scenarios/mysql/02-isolation/write-skew-rr.yaml:26 scenarios/mysql/02-isolation/write-skew-rr.yaml#steps[4].tl tl on-call count → 2 M29 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/02-isolation/write-skew-rr.yaml#steps[6].tl at scenarios/mysql/02-isolation/write-skew-rr.yaml:29 C00847 base scenarios/mysql/02-isolation/write-skew-rr.yaml:28 scenarios/mysql/02-isolation/write-skew-rr.yaml#steps[5].note note Each updates a DIFFERENT row, so there is no write-write conflict to detect. M29 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/02-isolation/write-skew-rr.yaml#steps[7].note at scenarios/mysql/02-isolation/write-skew-rr.yaml:31 C00848 base scenarios/mysql/02-isolation/write-skew-rr.yaml:29 scenarios/mysql/02-isolation/write-skew-rr.yaml#steps[6].A A UPDATE doctors SET on_call = false WHERE name = 'alice' M29 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/write-skew-rr.yaml#steps[8].A at scenarios/mysql/02-isolation/write-skew-rr.yaml:32 C00849 base scenarios/mysql/02-isolation/write-skew-rr.yaml:30 scenarios/mysql/02-isolation/write-skew-rr.yaml#steps[6].tl tl alice off call M29 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/02-isolation/write-skew-rr.yaml#steps[8].tl at scenarios/mysql/02-isolation/write-skew-rr.yaml:33 C00850 base scenarios/mysql/02-isolation/write-skew-rr.yaml:31 scenarios/mysql/02-isolation/write-skew-rr.yaml#steps[7].B B UPDATE doctors SET on_call = false WHERE name = 'bob' M29 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/write-skew-rr.yaml#steps[9].B at scenarios/mysql/02-isolation/write-skew-rr.yaml:34 C00851 base scenarios/mysql/02-isolation/write-skew-rr.yaml:32 scenarios/mysql/02-isolation/write-skew-rr.yaml#steps[7].tl tl bob off call M29 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/02-isolation/write-skew-rr.yaml#steps[9].tl at scenarios/mysql/02-isolation/write-skew-rr.yaml:35 C00852 base scenarios/mysql/02-isolation/write-skew-rr.yaml:34 scenarios/mysql/02-isolation/write-skew-rr.yaml#steps[8].A A COMMIT M29 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/write-skew-rr.yaml#steps[10].A at scenarios/mysql/02-isolation/write-skew-rr.yaml:37 C00853 base scenarios/mysql/02-isolation/write-skew-rr.yaml:35 scenarios/mysql/02-isolation/write-skew-rr.yaml#steps[8].tl tl COMMIT M29 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/02-isolation/write-skew-rr.yaml#steps[10].tl at scenarios/mysql/02-isolation/write-skew-rr.yaml:38 C00854 base scenarios/mysql/02-isolation/write-skew-rr.yaml:36 scenarios/mysql/02-isolation/write-skew-rr.yaml#steps[9].B B COMMIT M29 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/write-skew-rr.yaml#steps[11].B at scenarios/mysql/02-isolation/write-skew-rr.yaml:39 C00855 base scenarios/mysql/02-isolation/write-skew-rr.yaml:37 scenarios/mysql/02-isolation/write-skew-rr.yaml#steps[9].comment comment both succeed! M29 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/02-isolation/write-skew-rr.yaml#steps[11].comment at scenarios/mysql/02-isolation/write-skew-rr.yaml:40 C00856 base scenarios/mysql/02-isolation/write-skew-rr.yaml:38 scenarios/mysql/02-isolation/write-skew-rr.yaml#steps[9].tl tl COMMIT (both succeed) M29 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/02-isolation/write-skew-rr.yaml#steps[11].tl at scenarios/mysql/02-isolation/write-skew-rr.yaml:41 C00857 base scenarios/mysql/02-isolation/write-skew-rr.yaml:40 scenarios/mysql/02-isolation/write-skew-rr.yaml#steps[10].A A SELECT count(*) AS on_call FROM doctors WHERE on_call M29 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/write-skew-rr.yaml#steps[12].A at scenarios/mysql/02-isolation/write-skew-rr.yaml:43 C00858 base scenarios/mysql/02-isolation/write-skew-rr.yaml:41 scenarios/mysql/02-isolation/write-skew-rr.yaml#steps[10].expect[0].on_call on_call 0 M29 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/write-skew-rr.yaml#steps[12].expect[0].on_call at scenarios/mysql/02-isolation/write-skew-rr.yaml:44 C00859 base scenarios/mysql/02-isolation/write-skew-rr.yaml:42 scenarios/mysql/02-isolation/write-skew-rr.yaml#steps[10].comment comment nobody is on call — the invariant is broken M29 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Replaced at the corresponding logical occurrence; current occurrence scenarios/mysql/02-isolation/write-skew-rr.yaml#steps[12].comment at scenarios/mysql/02-isolation/write-skew-rr.yaml:45 C00860 base scenarios/mysql/02-isolation/write-skew-rr.yaml:43 scenarios/mysql/02-isolation/write-skew-rr.yaml#steps[10].tl tl on-call count → 0 — invariant broken M29 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Replaced at the corresponding logical occurrence; current occurrence scenarios/mysql/02-isolation/write-skew-rr.yaml#steps[12].tl at scenarios/mysql/02-isolation/write-skew-rr.yaml:46 C00861 base scenarios/mysql/02-isolation/write-skew-rr.yaml:45 scenarios/mysql/02-isolation/write-skew-rr.yaml#steps[11].note note Each transaction was internally consistent; together they broke the rule. Only SERIALIZABLE catches this. M29 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Replaced at the corresponding logical occurrence; current occurrence scenarios/mysql/02-isolation/write-skew-rr.yaml#steps[13].note at scenarios/mysql/02-isolation/write-skew-rr.yaml:48 C00862 base scenarios/mysql/02-isolation/write-skew-serializable.yaml:1 scenarios/mysql/02-isolation/write-skew-serializable.yaml#title title SERIALIZABLE catches write skew — with locks M30 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Replaced at the corresponding logical occurrence; current occurrence scenarios/mysql/02-isolation/write-skew-serializable.yaml#title at scenarios/mysql/02-isolation/write-skew-serializable.yaml:1 C00863 base scenarios/mysql/02-isolation/write-skew-serializable.yaml:2 scenarios/mysql/02-isolation/write-skew-serializable.yaml#claim claim Under MySQL's SERIALIZABLE, plain SELECTs take shared locks, so the write-skew interleaving deadlocks: one transaction is rolled back with errno 1213, and the invariant survives. M30 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Replaced at the corresponding logical occurrence; current occurrence scenarios/mysql/02-isolation/write-skew-serializable.yaml#claim at scenarios/mysql/02-isolation/write-skew-serializable.yaml:2 C00864 base scenarios/mysql/02-isolation/write-skew-serializable.yaml:6 scenarios/mysql/02-isolation/write-skew-serializable.yaml#anomaly anomaly G2 M30 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Replaced at the corresponding logical occurrence; current occurrence scenarios/mysql/02-isolation/write-skew-serializable.yaml#anomaly at scenarios/mysql/02-isolation/write-skew-serializable.yaml:7 C00865 base scenarios/mysql/02-isolation/write-skew-serializable.yaml:7 scenarios/mysql/02-isolation/write-skew-serializable.yaml#isolation isolation SERIALIZABLE M30 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/write-skew-serializable.yaml#isolation at scenarios/mysql/02-isolation/write-skew-serializable.yaml:8 C00866 base scenarios/mysql/02-isolation/write-skew-serializable.yaml:8 scenarios/mysql/02-isolation/write-skew-serializable.yaml#setup setup "CREATE TABLE doctors (name varchar(20) PRIMARY KEY, on_call boolean NOT NULL); INSERT INTO doctors VALUES ('alice', true), ('bob', true); " M30 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Replaced at the corresponding logical occurrence; current occurrence scenarios/mysql/02-isolation/write-skew-serializable.yaml#setup at scenarios/mysql/02-isolation/write-skew-serializable.yaml:9 C00867 base scenarios/mysql/02-isolation/write-skew-serializable.yaml:11 scenarios/mysql/02-isolation/write-skew-serializable.yaml#sessions[0] sessions[0] A M30 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/write-skew-serializable.yaml#sessions[0] at scenarios/mysql/02-isolation/write-skew-serializable.yaml:12 C00868 base scenarios/mysql/02-isolation/write-skew-serializable.yaml:11 scenarios/mysql/02-isolation/write-skew-serializable.yaml#sessions[1] sessions[1] B M30 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/write-skew-serializable.yaml#sessions[1] at scenarios/mysql/02-isolation/write-skew-serializable.yaml:12 C00869 base scenarios/mysql/02-isolation/write-skew-serializable.yaml:13 scenarios/mysql/02-isolation/write-skew-serializable.yaml#steps[0].note note Same story, same statements, same order — only the isolation level differs. M30 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Replaced at the corresponding logical occurrence; current occurrence scenarios/mysql/02-isolation/write-skew-serializable.yaml#steps[1].note at scenarios/mysql/02-isolation/write-skew-serializable.yaml:16 C00870 base scenarios/mysql/02-isolation/write-skew-serializable.yaml:14 scenarios/mysql/02-isolation/write-skew-serializable.yaml#steps[1].A A SET TRANSACTION ISOLATION LEVEL SERIALIZABLE M30 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=SERIALIZABLE, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/write-skew-serializable.yaml#steps[2].A at scenarios/mysql/02-isolation/write-skew-serializable.yaml:17 C00871 base scenarios/mysql/02-isolation/write-skew-serializable.yaml:15 scenarios/mysql/02-isolation/write-skew-serializable.yaml#steps[2].B B SET TRANSACTION ISOLATION LEVEL SERIALIZABLE M30 MySQL 8.4.11, InnoDB; before step: A=SERIALIZABLE, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=SERIALIZABLE, standalone/next transaction, autocommit=1; B=SERIALIZABLE, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/write-skew-serializable.yaml#steps[3].B at scenarios/mysql/02-isolation/write-skew-serializable.yaml:18 C00872 base scenarios/mysql/02-isolation/write-skew-serializable.yaml:16 scenarios/mysql/02-isolation/write-skew-serializable.yaml#steps[3].A A BEGIN M30 MySQL 8.4.11, InnoDB; before step: A=SERIALIZABLE, standalone/next transaction, autocommit=1; B=SERIALIZABLE, standalone/next transaction, autocommit=1; operation/expected value as recorded A=SERIALIZABLE, open transaction, autocommit=1; B=SERIALIZABLE, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/write-skew-serializable.yaml#steps[4].A at scenarios/mysql/02-isolation/write-skew-serializable.yaml:19 C00873 base scenarios/mysql/02-isolation/write-skew-serializable.yaml:17 scenarios/mysql/02-isolation/write-skew-serializable.yaml#steps[4].B B BEGIN M30 MySQL 8.4.11, InnoDB; before step: A=SERIALIZABLE, open transaction, autocommit=1; B=SERIALIZABLE, standalone/next transaction, autocommit=1; operation/expected value as recorded A=SERIALIZABLE, open transaction, autocommit=1; B=SERIALIZABLE, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/write-skew-serializable.yaml#steps[5].B at scenarios/mysql/02-isolation/write-skew-serializable.yaml:20 C00874 base scenarios/mysql/02-isolation/write-skew-serializable.yaml:19 scenarios/mysql/02-isolation/write-skew-serializable.yaml#steps[5].A A SELECT count(*) AS on_call FROM doctors WHERE on_call M30 MySQL 8.4.11, InnoDB; before step: A=SERIALIZABLE, open transaction, autocommit=1; B=SERIALIZABLE, open transaction, autocommit=1; operation/expected value as recorded A=SERIALIZABLE, open transaction, autocommit=1; B=SERIALIZABLE, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/write-skew-serializable.yaml#steps[6].A at scenarios/mysql/02-isolation/write-skew-serializable.yaml:22 C00875 base scenarios/mysql/02-isolation/write-skew-serializable.yaml:20 scenarios/mysql/02-isolation/write-skew-serializable.yaml#steps[5].expect[0].on_call on_call 2 M30 MySQL 8.4.11, InnoDB; before step: A=SERIALIZABLE, open transaction, autocommit=1; B=SERIALIZABLE, open transaction, autocommit=1; operation/expected value as recorded A=SERIALIZABLE, open transaction, autocommit=1; B=SERIALIZABLE, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/write-skew-serializable.yaml#steps[6].expect[0].on_call at scenarios/mysql/02-isolation/write-skew-serializable.yaml:23 C00876 base scenarios/mysql/02-isolation/write-skew-serializable.yaml:21 scenarios/mysql/02-isolation/write-skew-serializable.yaml#steps[5].tl tl on-call count → 2 (takes shared locks) M30 MySQL 8.4.11, InnoDB; before step: A=SERIALIZABLE, open transaction, autocommit=1; B=SERIALIZABLE, open transaction, autocommit=1; operation/expected value as recorded A=SERIALIZABLE, open transaction, autocommit=1; B=SERIALIZABLE, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/02-isolation/write-skew-serializable.yaml#steps[6].tl at scenarios/mysql/02-isolation/write-skew-serializable.yaml:24 C00877 base scenarios/mysql/02-isolation/write-skew-serializable.yaml:23 scenarios/mysql/02-isolation/write-skew-serializable.yaml#steps[6].B B SELECT count(*) AS on_call FROM doctors WHERE on_call M30 MySQL 8.4.11, InnoDB; before step: A=SERIALIZABLE, open transaction, autocommit=1; B=SERIALIZABLE, open transaction, autocommit=1; operation/expected value as recorded A=SERIALIZABLE, open transaction, autocommit=1; B=SERIALIZABLE, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/write-skew-serializable.yaml#steps[7].B at scenarios/mysql/02-isolation/write-skew-serializable.yaml:26 C00878 base scenarios/mysql/02-isolation/write-skew-serializable.yaml:24 scenarios/mysql/02-isolation/write-skew-serializable.yaml#steps[6].expect[0].on_call on_call 2 M30 MySQL 8.4.11, InnoDB; before step: A=SERIALIZABLE, open transaction, autocommit=1; B=SERIALIZABLE, open transaction, autocommit=1; operation/expected value as recorded A=SERIALIZABLE, open transaction, autocommit=1; B=SERIALIZABLE, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/write-skew-serializable.yaml#steps[7].expect[0].on_call at scenarios/mysql/02-isolation/write-skew-serializable.yaml:27 C00879 base scenarios/mysql/02-isolation/write-skew-serializable.yaml:25 scenarios/mysql/02-isolation/write-skew-serializable.yaml#steps[6].tl tl on-call count → 2 (takes shared locks) M30 MySQL 8.4.11, InnoDB; before step: A=SERIALIZABLE, open transaction, autocommit=1; B=SERIALIZABLE, open transaction, autocommit=1; operation/expected value as recorded A=SERIALIZABLE, open transaction, autocommit=1; B=SERIALIZABLE, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/02-isolation/write-skew-serializable.yaml#steps[7].tl at scenarios/mysql/02-isolation/write-skew-serializable.yaml:28 C00880 base scenarios/mysql/02-isolation/write-skew-serializable.yaml:27 scenarios/mysql/02-isolation/write-skew-serializable.yaml#steps[7].note note Those SELECTs took shared locks on the rows they read. A's write now waits for B… M30 MySQL 8.4.11, InnoDB; before step: A=SERIALIZABLE, open transaction, autocommit=1; B=SERIALIZABLE, open transaction, autocommit=1; operation/expected value as recorded A=SERIALIZABLE, open transaction, autocommit=1; B=SERIALIZABLE, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/02-isolation/write-skew-serializable.yaml#steps[8].note at scenarios/mysql/02-isolation/write-skew-serializable.yaml:30 C00881 base scenarios/mysql/02-isolation/write-skew-serializable.yaml:28 scenarios/mysql/02-isolation/write-skew-serializable.yaml#steps[8].A A UPDATE doctors SET on_call = false WHERE name = 'alice' M30 MySQL 8.4.11, InnoDB; before step: A=SERIALIZABLE, open transaction, autocommit=1; B=SERIALIZABLE, open transaction, autocommit=1; operation/expected value as recorded A=SERIALIZABLE, open transaction, autocommit=1; B=SERIALIZABLE, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/write-skew-serializable.yaml#steps[9].A at scenarios/mysql/02-isolation/write-skew-serializable.yaml:31 C00882 base scenarios/mysql/02-isolation/write-skew-serializable.yaml:29 scenarios/mysql/02-isolation/write-skew-serializable.yaml#steps[8].blocks blocks p1 M30 MySQL 8.4.11, InnoDB; before step: A=SERIALIZABLE, open transaction, autocommit=1; B=SERIALIZABLE, open transaction, autocommit=1; operation/expected value as recorded A=SERIALIZABLE, open transaction, autocommit=1; B=SERIALIZABLE, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/write-skew-serializable.yaml#steps[9].blocks at scenarios/mysql/02-isolation/write-skew-serializable.yaml:32 C00883 base scenarios/mysql/02-isolation/write-skew-serializable.yaml:30 scenarios/mysql/02-isolation/write-skew-serializable.yaml#steps[8].tl tl alice off call M30 MySQL 8.4.11, InnoDB; before step: A=SERIALIZABLE, open transaction, autocommit=1; B=SERIALIZABLE, open transaction, autocommit=1; operation/expected value as recorded A=SERIALIZABLE, open transaction, autocommit=1; B=SERIALIZABLE, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/02-isolation/write-skew-serializable.yaml#steps[9].tl at scenarios/mysql/02-isolation/write-skew-serializable.yaml:33 C00884 base scenarios/mysql/02-isolation/write-skew-serializable.yaml:32 scenarios/mysql/02-isolation/write-skew-serializable.yaml#steps[9].note note …and B's write closes the cycle. InnoDB detects the deadlock and rolls B back entirely. M30 MySQL 8.4.11, InnoDB; before step: A=SERIALIZABLE, open transaction, autocommit=1; B=SERIALIZABLE, open transaction, autocommit=1; operation/expected value as recorded A=SERIALIZABLE, open transaction, autocommit=1; B=SERIALIZABLE, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/02-isolation/write-skew-serializable.yaml#steps[10].note at scenarios/mysql/02-isolation/write-skew-serializable.yaml:35 C00885 base scenarios/mysql/02-isolation/write-skew-serializable.yaml:33 scenarios/mysql/02-isolation/write-skew-serializable.yaml#steps[10].B.fails fails UPDATE doctors SET on_call = false WHERE name = 'bob' M30 MySQL 8.4.11, InnoDB; before step: A=SERIALIZABLE, open transaction, autocommit=1; B=SERIALIZABLE, open transaction, autocommit=1; operation/expected value as recorded A=SERIALIZABLE, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/write-skew-serializable.yaml#steps[11].B.fails at scenarios/mysql/02-isolation/write-skew-serializable.yaml:36 C00886 base scenarios/mysql/02-isolation/write-skew-serializable.yaml:34 scenarios/mysql/02-isolation/write-skew-serializable.yaml#steps[10].error error 1213 M30 MySQL 8.4.11, InnoDB; before step: A=SERIALIZABLE, open transaction, autocommit=1; B=SERIALIZABLE, open transaction, autocommit=1; operation/expected value as recorded A=SERIALIZABLE, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/write-skew-serializable.yaml#steps[11].error at scenarios/mysql/02-isolation/write-skew-serializable.yaml:37 C00887 base scenarios/mysql/02-isolation/write-skew-serializable.yaml:35 scenarios/mysql/02-isolation/write-skew-serializable.yaml#steps[10].comment comment ER_LOCK_DEADLOCK M30 MySQL 8.4.11, InnoDB; before step: A=SERIALIZABLE, open transaction, autocommit=1; B=SERIALIZABLE, open transaction, autocommit=1; operation/expected value as recorded A=SERIALIZABLE, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/02-isolation/write-skew-serializable.yaml#steps[11].comment at scenarios/mysql/02-isolation/write-skew-serializable.yaml:38 C00888 base scenarios/mysql/02-isolation/write-skew-serializable.yaml:36 scenarios/mysql/02-isolation/write-skew-serializable.yaml#steps[10].tl tl bob off call M30 MySQL 8.4.11, InnoDB; before step: A=SERIALIZABLE, open transaction, autocommit=1; B=SERIALIZABLE, open transaction, autocommit=1; operation/expected value as recorded A=SERIALIZABLE, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/02-isolation/write-skew-serializable.yaml#steps[11].tl at scenarios/mysql/02-isolation/write-skew-serializable.yaml:39 C00889 base scenarios/mysql/02-isolation/write-skew-serializable.yaml:38 scenarios/mysql/02-isolation/write-skew-serializable.yaml#steps[11].note note B's rollback freed the locks — A's update proceeds. M30 MySQL 8.4.11, InnoDB; before step: A=SERIALIZABLE, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=SERIALIZABLE, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Replaced at the corresponding logical occurrence; current occurrence scenarios/mysql/02-isolation/write-skew-serializable.yaml#steps[12].note at scenarios/mysql/02-isolation/write-skew-serializable.yaml:41 C00890 base scenarios/mysql/02-isolation/write-skew-serializable.yaml:39 scenarios/mysql/02-isolation/write-skew-serializable.yaml#steps[12].success success p1 M30 MySQL 8.4.11, InnoDB; before step: A=SERIALIZABLE, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=SERIALIZABLE, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/write-skew-serializable.yaml#steps[13].success at scenarios/mysql/02-isolation/write-skew-serializable.yaml:42 C00891 base scenarios/mysql/02-isolation/write-skew-serializable.yaml:40 scenarios/mysql/02-isolation/write-skew-serializable.yaml#steps[13].A A COMMIT M30 MySQL 8.4.11, InnoDB; before step: A=SERIALIZABLE, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/write-skew-serializable.yaml#steps[14].A at scenarios/mysql/02-isolation/write-skew-serializable.yaml:43 C00892 base scenarios/mysql/02-isolation/write-skew-serializable.yaml:41 scenarios/mysql/02-isolation/write-skew-serializable.yaml#steps[13].tl tl COMMIT M30 MySQL 8.4.11, InnoDB; before step: A=SERIALIZABLE, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/02-isolation/write-skew-serializable.yaml#steps[14].tl at scenarios/mysql/02-isolation/write-skew-serializable.yaml:44 C00893 base scenarios/mysql/02-isolation/write-skew-serializable.yaml:43 scenarios/mysql/02-isolation/write-skew-serializable.yaml#steps[14].A A SELECT count(*) AS on_call FROM doctors WHERE on_call M30 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/write-skew-serializable.yaml#steps[15].A at scenarios/mysql/02-isolation/write-skew-serializable.yaml:46 C00894 base scenarios/mysql/02-isolation/write-skew-serializable.yaml:44 scenarios/mysql/02-isolation/write-skew-serializable.yaml#steps[14].expect[0].on_call on_call 1 M30 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Retained with scoped support; current occurrence scenarios/mysql/02-isolation/write-skew-serializable.yaml#steps[15].expect[0].on_call at scenarios/mysql/02-isolation/write-skew-serializable.yaml:47 C00895 base scenarios/mysql/02-isolation/write-skew-serializable.yaml:45 scenarios/mysql/02-isolation/write-skew-serializable.yaml#steps[14].comment comment the invariant survived M30 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Retained with scoped support; current occurrence scenarios/mysql/02-isolation/write-skew-serializable.yaml#steps[15].comment at scenarios/mysql/02-isolation/write-skew-serializable.yaml:48 C00896 base scenarios/mysql/02-isolation/write-skew-serializable.yaml:46 scenarios/mysql/02-isolation/write-skew-serializable.yaml#steps[14].tl tl on-call count → 1 — invariant survived M30 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Replaced at the corresponding logical occurrence; current occurrence scenarios/mysql/02-isolation/write-skew-serializable.yaml#steps[15].tl at scenarios/mysql/02-isolation/write-skew-serializable.yaml:49 C00897 base scenarios/mysql/02-isolation/write-skew-serializable.yaml:48 scenarios/mysql/02-isolation/write-skew-serializable.yaml#steps[15].note note PostgreSQL detects the same skew without blocking (SSI, at COMMIT). MySQL prevents it the classic way: locks and a deadlock victim. M30 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Replaced at the corresponding logical occurrence; current occurrence scenarios/mysql/02-isolation/write-skew-serializable.yaml#steps[16].note at scenarios/mysql/02-isolation/write-skew-serializable.yaml:51 C00898 base docs/mysql/01-basics/parts/aborted-transaction.md:1 scenarios/mysql/01-basics/aborted-transaction.yaml#Transcript.lines[1..32] generated-mirror Complete SQL/status/results, narrator paragraphs, timeline labels and verification footer, lines 1-32; claims are the exact source-field occurrences inventoried separately M10 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Demonstrated schedule mirror, not independent all-schedule evidence Retained with scoped support; current occurrence scenarios/mysql/01-basics/aborted-transaction.yaml#Transcript.lines[1..32] at docs/mysql/01-basics/parts/aborted-transaction.md:1 C00899 base docs/public/ledger.jsonl:1 scenarios/mysql/01-basics/aborted-transaction.yaml#ledger.scenario ledger-field """mysql/01-basics/aborted-transaction.yaml""" M10 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/01-basics/aborted-transaction.yaml#ledger.scenario at docs/public/ledger.jsonl:1 C00900 base docs/public/ledger.jsonl:1 scenarios/mysql/01-basics/aborted-transaction.yaml#ledger.engine ledger-field """mysql""" M10 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/01-basics/aborted-transaction.yaml#ledger.engine at docs/public/ledger.jsonl:1 C00901 base docs/public/ledger.jsonl:1 scenarios/mysql/01-basics/aborted-transaction.yaml#ledger.product ledger-field """MySQL""" M10 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/01-basics/aborted-transaction.yaml#ledger.product at docs/public/ledger.jsonl:1 C00902 base docs/public/ledger.jsonl:1 scenarios/mysql/01-basics/aborted-transaction.yaml#ledger.version ledger-field """8.4.11""" M10 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/01-basics/aborted-transaction.yaml#ledger.version at docs/public/ledger.jsonl:1 C00903 base docs/public/ledger.jsonl:1 scenarios/mysql/01-basics/aborted-transaction.yaml#ledger.claim ledger-field """After an error inside a transaction, MySQL keeps the transaction alive — only the failed statement is rolled back, and everything else commits normally.""" M10 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Replaced/removed; corrected current source in scenarios/mysql/01-basics/aborted-transaction.yaml, see semantic decisions A1-A10 C00904 base docs/public/ledger.jsonl:1 scenarios/mysql/01-basics/aborted-transaction.yaml#ledger.sessions ledger-field "[""A""]" M10 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/01-basics/aborted-transaction.yaml#ledger.sessions at docs/public/ledger.jsonl:1 C00905 base docs/public/ledger.jsonl:1 scenarios/mysql/01-basics/aborted-transaction.yaml#ledger.errors ledger-field "[""1062""]" M10 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/01-basics/aborted-transaction.yaml#ledger.errors at docs/public/ledger.jsonl:1 C00906 base docs/public/llms-full.txt:6 scenarios/mysql/01-basics/aborted-transaction.yaml#llms.section.lines[6..41] llms-mirror Complete attributed section, lines 6-41; metadata and Transcript mirror for this exact schedule, source-field claims inventoried separately M10 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated mirror, same support as its exact Transcript and source fields Retained with scoped support; current occurrence scenarios/mysql/01-basics/aborted-transaction.yaml#llms.section.lines[6..41] at docs/public/llms-full.txt:6 C00907 base docs/mysql/01-basics/parts/atomicity.md:1 scenarios/mysql/01-basics/atomicity.yaml#Transcript.lines[1..48] generated-mirror Complete SQL/status/results, narrator paragraphs, timeline labels and verification footer, lines 1-48; claims are the exact source-field occurrences inventoried separately M11 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Demonstrated schedule mirror, not independent all-schedule evidence Replaced/removed; corrected current source in scenarios/mysql/01-basics/atomicity.yaml, see semantic decisions A1-A10 C00908 base docs/public/ledger.jsonl:2 scenarios/mysql/01-basics/atomicity.yaml#ledger.scenario ledger-field """mysql/01-basics/atomicity.yaml""" M11 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/01-basics/atomicity.yaml#ledger.scenario at docs/public/ledger.jsonl:2 C00909 base docs/public/ledger.jsonl:2 scenarios/mysql/01-basics/atomicity.yaml#ledger.engine ledger-field """mysql""" M11 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/01-basics/atomicity.yaml#ledger.engine at docs/public/ledger.jsonl:2 C00910 base docs/public/ledger.jsonl:2 scenarios/mysql/01-basics/atomicity.yaml#ledger.product ledger-field """MySQL""" M11 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/01-basics/atomicity.yaml#ledger.product at docs/public/ledger.jsonl:2 C00911 base docs/public/ledger.jsonl:2 scenarios/mysql/01-basics/atomicity.yaml#ledger.version ledger-field """8.4.11""" M11 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/01-basics/atomicity.yaml#ledger.version at docs/public/ledger.jsonl:2 C00912 base docs/public/ledger.jsonl:2 scenarios/mysql/01-basics/atomicity.yaml#ledger.claim ledger-field """A transaction that fails halfway leaves zero partial writes — even statements that already succeeded inside it are undone.""" M11 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Replaced/removed; corrected current source in scenarios/mysql/01-basics/atomicity.yaml, see semantic decisions A1-A10 C00913 base docs/public/ledger.jsonl:2 scenarios/mysql/01-basics/atomicity.yaml#ledger.sessions ledger-field "[""A"",""B""]" M11 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/01-basics/atomicity.yaml#ledger.sessions at docs/public/ledger.jsonl:2 C00914 base docs/public/ledger.jsonl:2 scenarios/mysql/01-basics/atomicity.yaml#ledger.errors ledger-field "[""3819""]" M11 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/01-basics/atomicity.yaml#ledger.errors at docs/public/ledger.jsonl:2 C00915 base docs/public/llms-full.txt:42 scenarios/mysql/01-basics/atomicity.yaml#llms.section.lines[42..93] llms-mirror Complete attributed section, lines 42-93; metadata and Transcript mirror for this exact schedule, source-field claims inventoried separately M11 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated mirror, same support as its exact Transcript and source fields Replaced/removed; corrected current source in scenarios/mysql/01-basics/atomicity.yaml, see semantic decisions A1-A10 C00916 base docs/mysql/01-basics/parts/autocommit-visibility.md:1 scenarios/mysql/01-basics/autocommit-visibility.yaml#Transcript.lines[1..54] generated-mirror Complete SQL/status/results, narrator paragraphs, timeline labels and verification footer, lines 1-54; claims are the exact source-field occurrences inventoried separately M12 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Demonstrated schedule mirror, not independent all-schedule evidence Replaced/removed; corrected current source in scenarios/mysql/01-basics/autocommit-visibility.yaml, see semantic decisions A1-A10 C00917 base docs/public/ledger.jsonl:3 scenarios/mysql/01-basics/autocommit-visibility.yaml#ledger.scenario ledger-field """mysql/01-basics/autocommit-visibility.yaml""" M12 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/01-basics/autocommit-visibility.yaml#ledger.scenario at docs/public/ledger.jsonl:3 C00918 base docs/public/ledger.jsonl:3 scenarios/mysql/01-basics/autocommit-visibility.yaml#ledger.engine ledger-field """mysql""" M12 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/01-basics/autocommit-visibility.yaml#ledger.engine at docs/public/ledger.jsonl:3 C00919 base docs/public/ledger.jsonl:3 scenarios/mysql/01-basics/autocommit-visibility.yaml#ledger.product ledger-field """MySQL""" M12 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/01-basics/autocommit-visibility.yaml#ledger.product at docs/public/ledger.jsonl:3 C00920 base docs/public/ledger.jsonl:3 scenarios/mysql/01-basics/autocommit-visibility.yaml#ledger.version ledger-field """8.4.11""" M12 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/01-basics/autocommit-visibility.yaml#ledger.version at docs/public/ledger.jsonl:3 C00921 base docs/public/ledger.jsonl:3 scenarios/mysql/01-basics/autocommit-visibility.yaml#ledger.claim ledger-field """Without BEGIN, every statement commits instantly and is immediately visible to everyone; inside BEGIN, changes stay private until COMMIT.""" M12 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Replaced/removed; corrected current source in scenarios/mysql/01-basics/autocommit-visibility.yaml, see semantic decisions A1-A10 C00922 base docs/public/ledger.jsonl:3 scenarios/mysql/01-basics/autocommit-visibility.yaml#ledger.sessions ledger-field "[""A"",""B""]" M12 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/01-basics/autocommit-visibility.yaml#ledger.sessions at docs/public/ledger.jsonl:3 C00923 base docs/public/ledger.jsonl:3 scenarios/mysql/01-basics/autocommit-visibility.yaml#ledger.errors ledger-field [] M12 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/01-basics/autocommit-visibility.yaml#ledger.errors at docs/public/ledger.jsonl:3 C00924 base docs/public/llms-full.txt:94 scenarios/mysql/01-basics/autocommit-visibility.yaml#llms.section.lines[94..151] llms-mirror Complete attributed section, lines 94-151; metadata and Transcript mirror for this exact schedule, source-field claims inventoried separately M12 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated mirror, same support as its exact Transcript and source fields Replaced/removed; corrected current source in scenarios/mysql/01-basics/autocommit-visibility.yaml, see semantic decisions A1-A10 C00925 base docs/mysql/01-basics/parts/savepoint-nesting.md:1 scenarios/mysql/01-basics/savepoint-nesting.yaml#Transcript.lines[1..53] generated-mirror Complete SQL/status/results, narrator paragraphs, timeline labels and verification footer, lines 1-53; claims are the exact source-field occurrences inventoried separately M13 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Demonstrated schedule mirror, not independent all-schedule evidence Replaced/removed; corrected current source in scenarios/mysql/01-basics/savepoint-nesting.yaml, see semantic decisions A1-A10 C00926 base docs/public/ledger.jsonl:4 scenarios/mysql/01-basics/savepoint-nesting.yaml#ledger.scenario ledger-field """mysql/01-basics/savepoint-nesting.yaml""" M13 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/01-basics/savepoint-nesting.yaml#ledger.scenario at docs/public/ledger.jsonl:4 C00927 base docs/public/ledger.jsonl:4 scenarios/mysql/01-basics/savepoint-nesting.yaml#ledger.engine ledger-field """mysql""" M13 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/01-basics/savepoint-nesting.yaml#ledger.engine at docs/public/ledger.jsonl:4 C00928 base docs/public/ledger.jsonl:4 scenarios/mysql/01-basics/savepoint-nesting.yaml#ledger.product ledger-field """MySQL""" M13 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/01-basics/savepoint-nesting.yaml#ledger.product at docs/public/ledger.jsonl:4 C00929 base docs/public/ledger.jsonl:4 scenarios/mysql/01-basics/savepoint-nesting.yaml#ledger.version ledger-field """8.4.11""" M13 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/01-basics/savepoint-nesting.yaml#ledger.version at docs/public/ledger.jsonl:4 C00930 base docs/public/ledger.jsonl:4 scenarios/mysql/01-basics/savepoint-nesting.yaml#ledger.claim ledger-field """Rolling back to an outer savepoint discards inner savepoints along with their work; RELEASE keeps the changes but forfeits the rollback point.""" M13 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/01-basics/savepoint-nesting.yaml#ledger.claim at docs/public/ledger.jsonl:4 C00931 base docs/public/ledger.jsonl:4 scenarios/mysql/01-basics/savepoint-nesting.yaml#ledger.sessions ledger-field "[""A""]" M13 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/01-basics/savepoint-nesting.yaml#ledger.sessions at docs/public/ledger.jsonl:4 C00932 base docs/public/ledger.jsonl:4 scenarios/mysql/01-basics/savepoint-nesting.yaml#ledger.errors ledger-field "[""1305""]" M13 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/01-basics/savepoint-nesting.yaml#ledger.errors at docs/public/ledger.jsonl:4 C00933 base docs/public/llms-full.txt:152 scenarios/mysql/01-basics/savepoint-nesting.yaml#llms.section.lines[152..208] llms-mirror Complete attributed section, lines 152-208; metadata and Transcript mirror for this exact schedule, source-field claims inventoried separately M13 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated mirror, same support as its exact Transcript and source fields Replaced/removed; corrected current source in scenarios/mysql/01-basics/savepoint-nesting.yaml, see semantic decisions A1-A10 C00934 base docs/mysql/01-basics/parts/savepoint-recovery.md:1 scenarios/mysql/01-basics/savepoint-recovery.yaml#Transcript.lines[1..45] generated-mirror Complete SQL/status/results, narrator paragraphs, timeline labels and verification footer, lines 1-45; claims are the exact source-field occurrences inventoried separately M14 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Demonstrated schedule mirror, not independent all-schedule evidence Replaced/removed; corrected current source in scenarios/mysql/01-basics/savepoint-recovery.yaml, see semantic decisions A1-A10 C00935 base docs/public/ledger.jsonl:5 scenarios/mysql/01-basics/savepoint-recovery.yaml#ledger.scenario ledger-field """mysql/01-basics/savepoint-recovery.yaml""" M14 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/01-basics/savepoint-recovery.yaml#ledger.scenario at docs/public/ledger.jsonl:5 C00936 base docs/public/ledger.jsonl:5 scenarios/mysql/01-basics/savepoint-recovery.yaml#ledger.engine ledger-field """mysql""" M14 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/01-basics/savepoint-recovery.yaml#ledger.engine at docs/public/ledger.jsonl:5 C00937 base docs/public/ledger.jsonl:5 scenarios/mysql/01-basics/savepoint-recovery.yaml#ledger.product ledger-field """MySQL""" M14 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/01-basics/savepoint-recovery.yaml#ledger.product at docs/public/ledger.jsonl:5 C00938 base docs/public/ledger.jsonl:5 scenarios/mysql/01-basics/savepoint-recovery.yaml#ledger.version ledger-field """8.4.11""" M14 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/01-basics/savepoint-recovery.yaml#ledger.version at docs/public/ledger.jsonl:5 C00939 base docs/public/ledger.jsonl:5 scenarios/mysql/01-basics/savepoint-recovery.yaml#ledger.claim ledger-field """ROLLBACK TO SAVEPOINT discards only the work done after the savepoint — the rest of the transaction commits normally.""" M14 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Replaced/removed; corrected current source in scenarios/mysql/01-basics/savepoint-recovery.yaml, see semantic decisions A1-A10 C00940 base docs/public/ledger.jsonl:5 scenarios/mysql/01-basics/savepoint-recovery.yaml#ledger.sessions ledger-field "[""A""]" M14 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/01-basics/savepoint-recovery.yaml#ledger.sessions at docs/public/ledger.jsonl:5 C00941 base docs/public/ledger.jsonl:5 scenarios/mysql/01-basics/savepoint-recovery.yaml#ledger.errors ledger-field "[""1062""]" M14 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/01-basics/savepoint-recovery.yaml#ledger.errors at docs/public/ledger.jsonl:5 C00942 base docs/public/llms-full.txt:209 scenarios/mysql/01-basics/savepoint-recovery.yaml#llms.section.lines[209..257] llms-mirror Complete attributed section, lines 209-257; metadata and Transcript mirror for this exact schedule, source-field claims inventoried separately M14 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated mirror, same support as its exact Transcript and source fields Replaced/removed; corrected current source in scenarios/mysql/01-basics/savepoint-recovery.yaml, see semantic decisions A1-A10 C00943 base docs/mysql/02-isolation/parts/circular-information-flow.md:1 scenarios/mysql/02-isolation/circular-information-flow.yaml#Transcript.lines[1..96] generated-mirror Complete SQL/status/results, narrator paragraphs, timeline labels and verification footer, lines 1-96; claims are the exact source-field occurrences inventoried separately M15 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Demonstrated schedule mirror, not independent all-schedule evidence Replaced/removed; corrected current source in scenarios/mysql/02-isolation/circular-information-flow.yaml, see semantic decisions A1-A10 C00944 base docs/public/ledger.jsonl:6 scenarios/mysql/02-isolation/circular-information-flow.yaml#ledger.scenario ledger-field """mysql/02-isolation/circular-information-flow.yaml""" M15 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/02-isolation/circular-information-flow.yaml#ledger.scenario at docs/public/ledger.jsonl:6 C00945 base docs/public/ledger.jsonl:6 scenarios/mysql/02-isolation/circular-information-flow.yaml#ledger.engine ledger-field """mysql""" M15 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/02-isolation/circular-information-flow.yaml#ledger.engine at docs/public/ledger.jsonl:6 C00946 base docs/public/ledger.jsonl:6 scenarios/mysql/02-isolation/circular-information-flow.yaml#ledger.product ledger-field """MySQL""" M15 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/02-isolation/circular-information-flow.yaml#ledger.product at docs/public/ledger.jsonl:6 C00947 base docs/public/ledger.jsonl:6 scenarios/mysql/02-isolation/circular-information-flow.yaml#ledger.version ledger-field """8.4.11""" M15 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/02-isolation/circular-information-flow.yaml#ledger.version at docs/public/ledger.jsonl:6 C00948 base docs/public/ledger.jsonl:6 scenarios/mysql/02-isolation/circular-information-flow.yaml#ledger.claim ledger-field """At READ UNCOMMITTED two concurrent transactions can each read the other's uncommitted write (Adya's G1c, \""circular information flow\"") — an exchange no serial order can explain. READ COMMITTED makes it impossible.""" M15 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Replaced/removed; corrected current source in scenarios/mysql/02-isolation/circular-information-flow.yaml, see semantic decisions A1-A10 C00949 base docs/public/ledger.jsonl:6 scenarios/mysql/02-isolation/circular-information-flow.yaml#ledger.sessions ledger-field "[""A"",""B""]" M15 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/02-isolation/circular-information-flow.yaml#ledger.sessions at docs/public/ledger.jsonl:6 C00950 base docs/public/ledger.jsonl:6 scenarios/mysql/02-isolation/circular-information-flow.yaml#ledger.errors ledger-field [] M15 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/02-isolation/circular-information-flow.yaml#ledger.errors at docs/public/ledger.jsonl:6 C00951 base docs/public/ledger.jsonl:6 scenarios/mysql/02-isolation/circular-information-flow.yaml#ledger.anomaly ledger-field """G1c""" M15 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/02-isolation/circular-information-flow.yaml#ledger.anomaly at docs/public/ledger.jsonl:6 C00952 base docs/public/llms-full.txt:258 scenarios/mysql/02-isolation/circular-information-flow.yaml#llms.section.lines[258..357] llms-mirror Complete attributed section, lines 258-357; metadata and Transcript mirror for this exact schedule, source-field claims inventoried separately M15 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated mirror, same support as its exact Transcript and source fields Replaced/removed; corrected current source in scenarios/mysql/02-isolation/circular-information-flow.yaml, see semantic decisions A1-A10 C00953 base docs/mysql/02-isolation/parts/current-reads.md:1 scenarios/mysql/02-isolation/current-reads.yaml#Transcript.lines[1..95] generated-mirror Complete SQL/status/results, narrator paragraphs, timeline labels and verification footer, lines 1-95; claims are the exact source-field occurrences inventoried separately M16 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Demonstrated schedule mirror, not independent all-schedule evidence Replaced/removed; corrected current source in scenarios/mysql/02-isolation/current-reads.yaml, see semantic decisions A1-A10 C00954 base docs/public/ledger.jsonl:7 scenarios/mysql/02-isolation/current-reads.yaml#ledger.scenario ledger-field """mysql/02-isolation/current-reads.yaml""" M16 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/02-isolation/current-reads.yaml#ledger.scenario at docs/public/ledger.jsonl:7 C00955 base docs/public/ledger.jsonl:7 scenarios/mysql/02-isolation/current-reads.yaml#ledger.engine ledger-field """mysql""" M16 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/02-isolation/current-reads.yaml#ledger.engine at docs/public/ledger.jsonl:7 C00956 base docs/public/ledger.jsonl:7 scenarios/mysql/02-isolation/current-reads.yaml#ledger.product ledger-field """MySQL""" M16 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/02-isolation/current-reads.yaml#ledger.product at docs/public/ledger.jsonl:7 C00957 base docs/public/ledger.jsonl:7 scenarios/mysql/02-isolation/current-reads.yaml#ledger.version ledger-field """8.4.11""" M16 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/02-isolation/current-reads.yaml#ledger.version at docs/public/ledger.jsonl:7 C00958 base docs/public/ledger.jsonl:7 scenarios/mysql/02-isolation/current-reads.yaml#ledger.claim ledger-field """A REPEATABLE READ transaction's UPDATE operates on the CURRENT committed row, not on its snapshot — and afterwards the transaction sees its own write, so the 'repeatable' read changes.""" M16 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Replaced/removed; corrected current source in scenarios/mysql/02-isolation/current-reads.yaml, see semantic decisions A1-A10 C00959 base docs/public/ledger.jsonl:7 scenarios/mysql/02-isolation/current-reads.yaml#ledger.sessions ledger-field "[""A"",""B""]" M16 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/02-isolation/current-reads.yaml#ledger.sessions at docs/public/ledger.jsonl:7 C00960 base docs/public/ledger.jsonl:7 scenarios/mysql/02-isolation/current-reads.yaml#ledger.errors ledger-field [] M16 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/02-isolation/current-reads.yaml#ledger.errors at docs/public/ledger.jsonl:7 C00961 base docs/public/llms-full.txt:358 scenarios/mysql/02-isolation/current-reads.yaml#llms.section.lines[358..456] llms-mirror Complete attributed section, lines 358-456; metadata and Transcript mirror for this exact schedule, source-field claims inventoried separately M16 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated mirror, same support as its exact Transcript and source fields Replaced/removed; corrected current source in scenarios/mysql/02-isolation/current-reads.yaml, see semantic decisions A1-A10 C00962 base docs/mysql/02-isolation/parts/dirty-read.md:1 scenarios/mysql/02-isolation/dirty-read.yaml#Transcript.lines[1..56] generated-mirror Complete SQL/status/results, narrator paragraphs, timeline labels and verification footer, lines 1-56; claims are the exact source-field occurrences inventoried separately M17 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Demonstrated schedule mirror, not independent all-schedule evidence Retained with scoped support; current occurrence scenarios/mysql/02-isolation/dirty-read.yaml#Transcript.lines[1..56] at docs/mysql/02-isolation/parts/dirty-read.md:1 C00963 base docs/public/ledger.jsonl:8 scenarios/mysql/02-isolation/dirty-read.yaml#ledger.scenario ledger-field """mysql/02-isolation/dirty-read.yaml""" M17 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/02-isolation/dirty-read.yaml#ledger.scenario at docs/public/ledger.jsonl:8 C00964 base docs/public/ledger.jsonl:8 scenarios/mysql/02-isolation/dirty-read.yaml#ledger.engine ledger-field """mysql""" M17 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/02-isolation/dirty-read.yaml#ledger.engine at docs/public/ledger.jsonl:8 C00965 base docs/public/ledger.jsonl:8 scenarios/mysql/02-isolation/dirty-read.yaml#ledger.product ledger-field """MySQL""" M17 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/02-isolation/dirty-read.yaml#ledger.product at docs/public/ledger.jsonl:8 C00966 base docs/public/ledger.jsonl:8 scenarios/mysql/02-isolation/dirty-read.yaml#ledger.version ledger-field """8.4.11""" M17 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/02-isolation/dirty-read.yaml#ledger.version at docs/public/ledger.jsonl:8 C00967 base docs/public/ledger.jsonl:8 scenarios/mysql/02-isolation/dirty-read.yaml#ledger.claim ledger-field """At READ UNCOMMITTED, MySQL serves other transactions' uncommitted changes — including values that are later rolled back and thus never existed.""" M17 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Replaced/removed; corrected current source in scenarios/mysql/02-isolation/dirty-read.yaml, see semantic decisions A1-A10 C00968 base docs/public/ledger.jsonl:8 scenarios/mysql/02-isolation/dirty-read.yaml#ledger.sessions ledger-field "[""A"",""B""]" M17 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/02-isolation/dirty-read.yaml#ledger.sessions at docs/public/ledger.jsonl:8 C00969 base docs/public/ledger.jsonl:8 scenarios/mysql/02-isolation/dirty-read.yaml#ledger.errors ledger-field [] M17 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/02-isolation/dirty-read.yaml#ledger.errors at docs/public/ledger.jsonl:8 C00970 base docs/public/ledger.jsonl:8 scenarios/mysql/02-isolation/dirty-read.yaml#ledger.anomaly ledger-field """G1a""" M17 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/02-isolation/dirty-read.yaml#ledger.anomaly at docs/public/ledger.jsonl:8 C00971 base docs/public/ledger.jsonl:8 scenarios/mysql/02-isolation/dirty-read.yaml#ledger.isolation ledger-field """READ UNCOMMITTED""" M17 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/02-isolation/dirty-read.yaml#ledger.isolation at docs/public/ledger.jsonl:8 C00972 base docs/public/llms-full.txt:457 scenarios/mysql/02-isolation/dirty-read.yaml#llms.section.lines[457..516] llms-mirror Complete attributed section, lines 457-516; metadata and Transcript mirror for this exact schedule, source-field claims inventoried separately M17 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated mirror, same support as its exact Transcript and source fields Replaced/removed; corrected current source in scenarios/mysql/02-isolation/dirty-read.yaml, see semantic decisions A1-A10 C00973 base docs/mysql/02-isolation/parts/dirty-write.md:1 scenarios/mysql/02-isolation/dirty-write.yaml#Transcript.lines[1..62] generated-mirror Complete SQL/status/results, narrator paragraphs, timeline labels and verification footer, lines 1-62; claims are the exact source-field occurrences inventoried separately M18 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Demonstrated schedule mirror, not independent all-schedule evidence Retained with scoped support; current occurrence scenarios/mysql/02-isolation/dirty-write.yaml#Transcript.lines[1..62] at docs/mysql/02-isolation/parts/dirty-write.md:1 C00974 base docs/public/ledger.jsonl:9 scenarios/mysql/02-isolation/dirty-write.yaml#ledger.scenario ledger-field """mysql/02-isolation/dirty-write.yaml""" M18 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/02-isolation/dirty-write.yaml#ledger.scenario at docs/public/ledger.jsonl:9 C00975 base docs/public/ledger.jsonl:9 scenarios/mysql/02-isolation/dirty-write.yaml#ledger.engine ledger-field """mysql""" M18 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/02-isolation/dirty-write.yaml#ledger.engine at docs/public/ledger.jsonl:9 C00976 base docs/public/ledger.jsonl:9 scenarios/mysql/02-isolation/dirty-write.yaml#ledger.product ledger-field """MySQL""" M18 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/02-isolation/dirty-write.yaml#ledger.product at docs/public/ledger.jsonl:9 C00977 base docs/public/ledger.jsonl:9 scenarios/mysql/02-isolation/dirty-write.yaml#ledger.version ledger-field """8.4.11""" M18 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/02-isolation/dirty-write.yaml#ledger.version at docs/public/ledger.jsonl:9 C00978 base docs/public/ledger.jsonl:9 scenarios/mysql/02-isolation/dirty-write.yaml#ledger.claim ledger-field """InnoDB always takes exclusive row locks for writes, so two transactions repricing the same rows cannot interleave their writes (Adya's G0, \""dirty write\"") at any isolation level — even the one that allows dirty reads.""" M18 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Replaced/removed; corrected current source in scenarios/mysql/02-isolation/dirty-write.yaml, see semantic decisions A1-A10 C00979 base docs/public/ledger.jsonl:9 scenarios/mysql/02-isolation/dirty-write.yaml#ledger.sessions ledger-field "[""A"",""B""]" M18 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/02-isolation/dirty-write.yaml#ledger.sessions at docs/public/ledger.jsonl:9 C00980 base docs/public/ledger.jsonl:9 scenarios/mysql/02-isolation/dirty-write.yaml#ledger.errors ledger-field [] M18 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/02-isolation/dirty-write.yaml#ledger.errors at docs/public/ledger.jsonl:9 C00981 base docs/public/ledger.jsonl:9 scenarios/mysql/02-isolation/dirty-write.yaml#ledger.anomaly ledger-field """G0""" M18 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/02-isolation/dirty-write.yaml#ledger.anomaly at docs/public/ledger.jsonl:9 C00982 base docs/public/ledger.jsonl:9 scenarios/mysql/02-isolation/dirty-write.yaml#ledger.isolation ledger-field """READ UNCOMMITTED""" M18 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/02-isolation/dirty-write.yaml#ledger.isolation at docs/public/ledger.jsonl:9 C00983 base docs/public/llms-full.txt:517 scenarios/mysql/02-isolation/dirty-write.yaml#llms.section.lines[517..582] llms-mirror Complete attributed section, lines 517-582; metadata and Transcript mirror for this exact schedule, source-field claims inventoried separately M18 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated mirror, same support as its exact Transcript and source fields Replaced/removed; corrected current source in scenarios/mysql/02-isolation/dirty-write.yaml, see semantic decisions A1-A10 C00984 base docs/mysql/02-isolation/parts/intermediate-read.md:1 scenarios/mysql/02-isolation/intermediate-read.yaml#Transcript.lines[1..76] generated-mirror Complete SQL/status/results, narrator paragraphs, timeline labels and verification footer, lines 1-76; claims are the exact source-field occurrences inventoried separately M19 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Demonstrated schedule mirror, not independent all-schedule evidence Retained with scoped support; current occurrence scenarios/mysql/02-isolation/intermediate-read.yaml#Transcript.lines[1..76] at docs/mysql/02-isolation/parts/intermediate-read.md:1 C00985 base docs/public/ledger.jsonl:10 scenarios/mysql/02-isolation/intermediate-read.yaml#ledger.scenario ledger-field """mysql/02-isolation/intermediate-read.yaml""" M19 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/02-isolation/intermediate-read.yaml#ledger.scenario at docs/public/ledger.jsonl:10 C00986 base docs/public/ledger.jsonl:10 scenarios/mysql/02-isolation/intermediate-read.yaml#ledger.engine ledger-field """mysql""" M19 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/02-isolation/intermediate-read.yaml#ledger.engine at docs/public/ledger.jsonl:10 C00987 base docs/public/ledger.jsonl:10 scenarios/mysql/02-isolation/intermediate-read.yaml#ledger.product ledger-field """MySQL""" M19 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/02-isolation/intermediate-read.yaml#ledger.product at docs/public/ledger.jsonl:10 C00988 base docs/public/ledger.jsonl:10 scenarios/mysql/02-isolation/intermediate-read.yaml#ledger.version ledger-field """8.4.11""" M19 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/02-isolation/intermediate-read.yaml#ledger.version at docs/public/ledger.jsonl:10 C00989 base docs/public/ledger.jsonl:10 scenarios/mysql/02-isolation/intermediate-read.yaml#ledger.claim ledger-field """At READ UNCOMMITTED a reader can observe an intermediate value the writer later overwrites before committing (Adya's G1b, \""intermediate read\"") — a number that is never part of any committed state. READ COMMITTED stops this.""" M19 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Replaced/removed; corrected current source in scenarios/mysql/02-isolation/intermediate-read.yaml, see semantic decisions A1-A10 C00990 base docs/public/ledger.jsonl:10 scenarios/mysql/02-isolation/intermediate-read.yaml#ledger.sessions ledger-field "[""A"",""B""]" M19 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/02-isolation/intermediate-read.yaml#ledger.sessions at docs/public/ledger.jsonl:10 C00991 base docs/public/ledger.jsonl:10 scenarios/mysql/02-isolation/intermediate-read.yaml#ledger.errors ledger-field [] M19 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/02-isolation/intermediate-read.yaml#ledger.errors at docs/public/ledger.jsonl:10 C00992 base docs/public/ledger.jsonl:10 scenarios/mysql/02-isolation/intermediate-read.yaml#ledger.anomaly ledger-field """G1b""" M19 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/02-isolation/intermediate-read.yaml#ledger.anomaly at docs/public/ledger.jsonl:10 C00993 base docs/public/llms-full.txt:583 scenarios/mysql/02-isolation/intermediate-read.yaml#llms.section.lines[583..662] llms-mirror Complete attributed section, lines 583-662; metadata and Transcript mirror for this exact schedule, source-field claims inventoried separately M19 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated mirror, same support as its exact Transcript and source fields Replaced/removed; corrected current source in scenarios/mysql/02-isolation/intermediate-read.yaml, see semantic decisions A1-A10 C00994 base docs/mysql/02-isolation/parts/lost-update-read-committed.md:1 scenarios/mysql/02-isolation/lost-update-read-committed.yaml#Transcript.lines[1..65] generated-mirror Complete SQL/status/results, narrator paragraphs, timeline labels and verification footer, lines 1-65; claims are the exact source-field occurrences inventoried separately M20 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Demonstrated schedule mirror, not independent all-schedule evidence Retained with scoped support; current occurrence scenarios/mysql/02-isolation/lost-update-read-committed.yaml#Transcript.lines[1..65] at docs/mysql/02-isolation/parts/lost-update-read-committed.md:1 C00995 base docs/public/ledger.jsonl:11 scenarios/mysql/02-isolation/lost-update-read-committed.yaml#ledger.scenario ledger-field """mysql/02-isolation/lost-update-read-committed.yaml""" M20 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/02-isolation/lost-update-read-committed.yaml#ledger.scenario at docs/public/ledger.jsonl:11 C00996 base docs/public/ledger.jsonl:11 scenarios/mysql/02-isolation/lost-update-read-committed.yaml#ledger.engine ledger-field """mysql""" M20 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/02-isolation/lost-update-read-committed.yaml#ledger.engine at docs/public/ledger.jsonl:11 C00997 base docs/public/ledger.jsonl:11 scenarios/mysql/02-isolation/lost-update-read-committed.yaml#ledger.product ledger-field """MySQL""" M20 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/02-isolation/lost-update-read-committed.yaml#ledger.product at docs/public/ledger.jsonl:11 C00998 base docs/public/ledger.jsonl:11 scenarios/mysql/02-isolation/lost-update-read-committed.yaml#ledger.version ledger-field """8.4.11""" M20 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/02-isolation/lost-update-read-committed.yaml#ledger.version at docs/public/ledger.jsonl:11 C00999 base docs/public/ledger.jsonl:11 scenarios/mysql/02-isolation/lost-update-read-committed.yaml#ledger.claim ledger-field """Two read-modify-write transactions at READ COMMITTED can silently overwrite each other: two deposits of 10 grow the balance by only 10.""" M20 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/02-isolation/lost-update-read-committed.yaml#ledger.claim at docs/public/ledger.jsonl:11 C01000 base docs/public/ledger.jsonl:11 scenarios/mysql/02-isolation/lost-update-read-committed.yaml#ledger.sessions ledger-field "[""A"",""B""]" M20 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/02-isolation/lost-update-read-committed.yaml#ledger.sessions at docs/public/ledger.jsonl:11 C01001 base docs/public/ledger.jsonl:11 scenarios/mysql/02-isolation/lost-update-read-committed.yaml#ledger.errors ledger-field [] M20 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/02-isolation/lost-update-read-committed.yaml#ledger.errors at docs/public/ledger.jsonl:11 C01002 base docs/public/ledger.jsonl:11 scenarios/mysql/02-isolation/lost-update-read-committed.yaml#ledger.anomaly ledger-field """P4""" M20 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/02-isolation/lost-update-read-committed.yaml#ledger.anomaly at docs/public/ledger.jsonl:11 C01003 base docs/public/ledger.jsonl:11 scenarios/mysql/02-isolation/lost-update-read-committed.yaml#ledger.isolation ledger-field """READ COMMITTED""" M20 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/02-isolation/lost-update-read-committed.yaml#ledger.isolation at docs/public/ledger.jsonl:11 C01004 base docs/public/llms-full.txt:663 scenarios/mysql/02-isolation/lost-update-read-committed.yaml#llms.section.lines[663..731] llms-mirror Complete attributed section, lines 663-731; metadata and Transcript mirror for this exact schedule, source-field claims inventoried separately M20 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated mirror, same support as its exact Transcript and source fields Replaced/removed; corrected current source in scenarios/mysql/02-isolation/lost-update-read-committed.yaml, see semantic decisions A1-A10 C01005 base docs/mysql/02-isolation/parts/lost-update-repeatable-read.md:1 scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml#Transcript.lines[1..59] generated-mirror Complete SQL/status/results, narrator paragraphs, timeline labels and verification footer, lines 1-59; claims are the exact source-field occurrences inventoried separately M21 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Demonstrated schedule mirror, not independent all-schedule evidence Replaced/removed; corrected current source in scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml, see semantic decisions A1-A10 C01006 base docs/public/ledger.jsonl:12 scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml#ledger.scenario ledger-field """mysql/02-isolation/lost-update-repeatable-read.yaml""" M21 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml#ledger.scenario at docs/public/ledger.jsonl:12 C01007 base docs/public/ledger.jsonl:12 scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml#ledger.engine ledger-field """mysql""" M21 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml#ledger.engine at docs/public/ledger.jsonl:12 C01008 base docs/public/ledger.jsonl:12 scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml#ledger.product ledger-field """MySQL""" M21 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml#ledger.product at docs/public/ledger.jsonl:12 C01009 base docs/public/ledger.jsonl:12 scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml#ledger.version ledger-field """8.4.11""" M21 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml#ledger.version at docs/public/ledger.jsonl:12 C01010 base docs/public/ledger.jsonl:12 scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml#ledger.claim ledger-field """The interleaving that loses an update at READ COMMITTED loses it at REPEATABLE READ too — MySQL raises no error, unlike PostgreSQL's 40001. The fix must be a locking read or an atomic UPDATE.""" M21 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Replaced/removed; corrected current source in scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml, see semantic decisions A1-A10 C01011 base docs/public/ledger.jsonl:12 scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml#ledger.sessions ledger-field "[""A"",""B""]" M21 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml#ledger.sessions at docs/public/ledger.jsonl:12 C01012 base docs/public/ledger.jsonl:12 scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml#ledger.errors ledger-field [] M21 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml#ledger.errors at docs/public/ledger.jsonl:12 C01013 base docs/public/ledger.jsonl:12 scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml#ledger.anomaly ledger-field """P4""" M21 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml#ledger.anomaly at docs/public/ledger.jsonl:12 C01014 base docs/public/llms-full.txt:732 scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml#llms.section.lines[732..794] llms-mirror Complete attributed section, lines 732-794; metadata and Transcript mirror for this exact schedule, source-field claims inventoried separately M21 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated mirror, same support as its exact Transcript and source fields Replaced/removed; corrected current source in scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml, see semantic decisions A1-A10 C01015 base docs/mysql/02-isolation/parts/non-repeatable-read.md:1 scenarios/mysql/02-isolation/non-repeatable-read.yaml#Transcript.lines[1..64] generated-mirror Complete SQL/status/results, narrator paragraphs, timeline labels and verification footer, lines 1-64; claims are the exact source-field occurrences inventoried separately M22 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Demonstrated schedule mirror, not independent all-schedule evidence Retained with scoped support; current occurrence scenarios/mysql/02-isolation/non-repeatable-read.yaml#Transcript.lines[1..64] at docs/mysql/02-isolation/parts/non-repeatable-read.md:1 C01016 base docs/public/ledger.jsonl:13 scenarios/mysql/02-isolation/non-repeatable-read.yaml#ledger.scenario ledger-field """mysql/02-isolation/non-repeatable-read.yaml""" M22 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/02-isolation/non-repeatable-read.yaml#ledger.scenario at docs/public/ledger.jsonl:13 C01017 base docs/public/ledger.jsonl:13 scenarios/mysql/02-isolation/non-repeatable-read.yaml#ledger.engine ledger-field """mysql""" M22 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/02-isolation/non-repeatable-read.yaml#ledger.engine at docs/public/ledger.jsonl:13 C01018 base docs/public/ledger.jsonl:13 scenarios/mysql/02-isolation/non-repeatable-read.yaml#ledger.product ledger-field """MySQL""" M22 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/02-isolation/non-repeatable-read.yaml#ledger.product at docs/public/ledger.jsonl:13 C01019 base docs/public/ledger.jsonl:13 scenarios/mysql/02-isolation/non-repeatable-read.yaml#ledger.version ledger-field """8.4.11""" M22 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/02-isolation/non-repeatable-read.yaml#ledger.version at docs/public/ledger.jsonl:13 C01020 base docs/public/ledger.jsonl:13 scenarios/mysql/02-isolation/non-repeatable-read.yaml#ledger.claim ledger-field """At READ COMMITTED, a transaction can read two different values for the same row — other transactions' commits become visible between its statements.""" M22 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Replaced/removed; corrected current source in scenarios/mysql/02-isolation/non-repeatable-read.yaml, see semantic decisions A1-A10 C01021 base docs/public/ledger.jsonl:13 scenarios/mysql/02-isolation/non-repeatable-read.yaml#ledger.sessions ledger-field "[""A"",""B""]" M22 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/02-isolation/non-repeatable-read.yaml#ledger.sessions at docs/public/ledger.jsonl:13 C01022 base docs/public/ledger.jsonl:13 scenarios/mysql/02-isolation/non-repeatable-read.yaml#ledger.errors ledger-field [] M22 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/02-isolation/non-repeatable-read.yaml#ledger.errors at docs/public/ledger.jsonl:13 C01023 base docs/public/ledger.jsonl:13 scenarios/mysql/02-isolation/non-repeatable-read.yaml#ledger.anomaly ledger-field """P2""" M22 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/02-isolation/non-repeatable-read.yaml#ledger.anomaly at docs/public/ledger.jsonl:13 C01024 base docs/public/ledger.jsonl:13 scenarios/mysql/02-isolation/non-repeatable-read.yaml#ledger.isolation ledger-field """READ COMMITTED""" M22 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/02-isolation/non-repeatable-read.yaml#ledger.isolation at docs/public/ledger.jsonl:13 C01025 base docs/public/llms-full.txt:795 scenarios/mysql/02-isolation/non-repeatable-read.yaml#llms.section.lines[795..862] llms-mirror Complete attributed section, lines 795-862; metadata and Transcript mirror for this exact schedule, source-field claims inventoried separately M22 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated mirror, same support as its exact Transcript and source fields Replaced/removed; corrected current source in scenarios/mysql/02-isolation/non-repeatable-read.yaml, see semantic decisions A1-A10 C01026 base docs/mysql/02-isolation/parts/observed-transaction-vanishes.md:1 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#Transcript.lines[1..109] generated-mirror Complete SQL/status/results, narrator paragraphs, timeline labels and verification footer, lines 1-109; claims are the exact source-field occurrences inventoried separately M23 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Demonstrated schedule mirror, not independent all-schedule evidence Retained with scoped support; current occurrence scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#Transcript.lines[1..109] at docs/mysql/02-isolation/parts/observed-transaction-vanishes.md:1 C01027 base docs/public/ledger.jsonl:14 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#ledger.scenario ledger-field """mysql/02-isolation/observed-transaction-vanishes.yaml""" M23 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#ledger.scenario at docs/public/ledger.jsonl:14 C01028 base docs/public/ledger.jsonl:14 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#ledger.engine ledger-field """mysql""" M23 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#ledger.engine at docs/public/ledger.jsonl:14 C01029 base docs/public/ledger.jsonl:14 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#ledger.product ledger-field """MySQL""" M23 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#ledger.product at docs/public/ledger.jsonl:14 C01030 base docs/public/ledger.jsonl:14 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#ledger.version ledger-field """8.4.11""" M23 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#ledger.version at docs/public/ledger.jsonl:14 C01031 base docs/public/ledger.jsonl:14 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#ledger.claim ledger-field """At READ UNCOMMITTED a reader can see a later transaction's uncommitted overwrite of one row while relying on the overwritten transaction's other row (Adya's OTV, \""observed transaction vanishes\"") — the committed transaction is visible only in pieces. READ COMMITTED restores atomic visibility.""" M23 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Replaced/removed; corrected current source in scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml, see semantic decisions A1-A10 C01032 base docs/public/ledger.jsonl:14 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#ledger.sessions ledger-field "[""A"",""B"",""C""]" M23 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#ledger.sessions at docs/public/ledger.jsonl:14 C01033 base docs/public/ledger.jsonl:14 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#ledger.errors ledger-field [] M23 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#ledger.errors at docs/public/ledger.jsonl:14 C01034 base docs/public/ledger.jsonl:14 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#ledger.anomaly ledger-field """OTV""" M23 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#ledger.anomaly at docs/public/ledger.jsonl:14 C01035 base docs/public/llms-full.txt:863 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#llms.section.lines[863..975] llms-mirror Complete attributed section, lines 863-975; metadata and Transcript mirror for this exact schedule, source-field claims inventoried separately M23 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated mirror, same support as its exact Transcript and source fields Replaced/removed; corrected current source in scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml, see semantic decisions A1-A10 C01036 base docs/mysql/02-isolation/parts/phantom-read.md:1 scenarios/mysql/02-isolation/phantom-read.yaml#Transcript.lines[1..43] generated-mirror Complete SQL/status/results, narrator paragraphs, timeline labels and verification footer, lines 1-43; claims are the exact source-field occurrences inventoried separately M24 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Demonstrated schedule mirror, not independent all-schedule evidence Retained with scoped support; current occurrence scenarios/mysql/02-isolation/phantom-read.yaml#Transcript.lines[1..43] at docs/mysql/02-isolation/parts/phantom-read.md:1 C01037 base docs/public/ledger.jsonl:15 scenarios/mysql/02-isolation/phantom-read.yaml#ledger.scenario ledger-field """mysql/02-isolation/phantom-read.yaml""" M24 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/02-isolation/phantom-read.yaml#ledger.scenario at docs/public/ledger.jsonl:15 C01038 base docs/public/ledger.jsonl:15 scenarios/mysql/02-isolation/phantom-read.yaml#ledger.engine ledger-field """mysql""" M24 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/02-isolation/phantom-read.yaml#ledger.engine at docs/public/ledger.jsonl:15 C01039 base docs/public/ledger.jsonl:15 scenarios/mysql/02-isolation/phantom-read.yaml#ledger.product ledger-field """MySQL""" M24 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/02-isolation/phantom-read.yaml#ledger.product at docs/public/ledger.jsonl:15 C01040 base docs/public/ledger.jsonl:15 scenarios/mysql/02-isolation/phantom-read.yaml#ledger.version ledger-field """8.4.11""" M24 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/02-isolation/phantom-read.yaml#ledger.version at docs/public/ledger.jsonl:15 C01041 base docs/public/ledger.jsonl:15 scenarios/mysql/02-isolation/phantom-read.yaml#ledger.claim ledger-field """At READ COMMITTED, re-running the same range query inside one transaction can return rows that weren't there before — phantoms.""" M24 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Replaced/removed; corrected current source in scenarios/mysql/02-isolation/phantom-read.yaml, see semantic decisions A1-A10 C01042 base docs/public/ledger.jsonl:15 scenarios/mysql/02-isolation/phantom-read.yaml#ledger.sessions ledger-field "[""A"",""B""]" M24 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/02-isolation/phantom-read.yaml#ledger.sessions at docs/public/ledger.jsonl:15 C01043 base docs/public/ledger.jsonl:15 scenarios/mysql/02-isolation/phantom-read.yaml#ledger.errors ledger-field [] M24 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/02-isolation/phantom-read.yaml#ledger.errors at docs/public/ledger.jsonl:15 C01044 base docs/public/ledger.jsonl:15 scenarios/mysql/02-isolation/phantom-read.yaml#ledger.anomaly ledger-field """PMP""" M24 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/02-isolation/phantom-read.yaml#ledger.anomaly at docs/public/ledger.jsonl:15 C01045 base docs/public/ledger.jsonl:15 scenarios/mysql/02-isolation/phantom-read.yaml#ledger.isolation ledger-field """READ COMMITTED""" M24 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/02-isolation/phantom-read.yaml#ledger.isolation at docs/public/ledger.jsonl:15 C01046 base docs/public/llms-full.txt:976 scenarios/mysql/02-isolation/phantom-read.yaml#llms.section.lines[976..1022] llms-mirror Complete attributed section, lines 976-1022; metadata and Transcript mirror for this exact schedule, source-field claims inventoried separately M24 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated mirror, same support as its exact Transcript and source fields Replaced/removed; corrected current source in scenarios/mysql/02-isolation/phantom-read.yaml, see semantic decisions A1-A10 C01047 base docs/mysql/02-isolation/parts/read-skew.md:1 scenarios/mysql/02-isolation/read-skew.yaml#Transcript.lines[1..85] generated-mirror Complete SQL/status/results, narrator paragraphs, timeline labels and verification footer, lines 1-85; claims are the exact source-field occurrences inventoried separately M25 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Demonstrated schedule mirror, not independent all-schedule evidence Retained with scoped support; current occurrence scenarios/mysql/02-isolation/read-skew.yaml#Transcript.lines[1..85] at docs/mysql/02-isolation/parts/read-skew.md:1 C01048 base docs/public/ledger.jsonl:16 scenarios/mysql/02-isolation/read-skew.yaml#ledger.scenario ledger-field """mysql/02-isolation/read-skew.yaml""" M25 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/02-isolation/read-skew.yaml#ledger.scenario at docs/public/ledger.jsonl:16 C01049 base docs/public/ledger.jsonl:16 scenarios/mysql/02-isolation/read-skew.yaml#ledger.engine ledger-field """mysql""" M25 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/02-isolation/read-skew.yaml#ledger.engine at docs/public/ledger.jsonl:16 C01050 base docs/public/ledger.jsonl:16 scenarios/mysql/02-isolation/read-skew.yaml#ledger.product ledger-field """MySQL""" M25 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/02-isolation/read-skew.yaml#ledger.product at docs/public/ledger.jsonl:16 C01051 base docs/public/ledger.jsonl:16 scenarios/mysql/02-isolation/read-skew.yaml#ledger.version ledger-field """8.4.11""" M25 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/02-isolation/read-skew.yaml#ledger.version at docs/public/ledger.jsonl:16 C01052 base docs/public/ledger.jsonl:16 scenarios/mysql/02-isolation/read-skew.yaml#ledger.claim ledger-field """At READ COMMITTED, a transaction reading two rows around a concurrent transfer observes money that never existed (Adya's G-single, \""read skew\""); REPEATABLE READ's transaction-wide snapshot keeps plain SELECTs consistent.""" M25 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Replaced/removed; corrected current source in scenarios/mysql/02-isolation/read-skew.yaml, see semantic decisions A1-A10 C01053 base docs/public/ledger.jsonl:16 scenarios/mysql/02-isolation/read-skew.yaml#ledger.sessions ledger-field "[""A"",""B""]" M25 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/02-isolation/read-skew.yaml#ledger.sessions at docs/public/ledger.jsonl:16 C01054 base docs/public/ledger.jsonl:16 scenarios/mysql/02-isolation/read-skew.yaml#ledger.errors ledger-field [] M25 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/02-isolation/read-skew.yaml#ledger.errors at docs/public/ledger.jsonl:16 C01055 base docs/public/ledger.jsonl:16 scenarios/mysql/02-isolation/read-skew.yaml#ledger.anomaly ledger-field """G-single""" M25 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/02-isolation/read-skew.yaml#ledger.anomaly at docs/public/ledger.jsonl:16 C01056 base docs/public/llms-full.txt:1023 scenarios/mysql/02-isolation/read-skew.yaml#llms.section.lines[1023..1111] llms-mirror Complete attributed section, lines 1023-1111; metadata and Transcript mirror for this exact schedule, source-field claims inventoried separately M25 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated mirror, same support as its exact Transcript and source fields Replaced/removed; corrected current source in scenarios/mysql/02-isolation/read-skew.yaml, see semantic decisions A1-A10 C01057 base docs/mysql/02-isolation/parts/stable-snapshot.md:1 scenarios/mysql/02-isolation/stable-snapshot.yaml#Transcript.lines[1..60] generated-mirror Complete SQL/status/results, narrator paragraphs, timeline labels and verification footer, lines 1-60; claims are the exact source-field occurrences inventoried separately M26 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Demonstrated schedule mirror, not independent all-schedule evidence Replaced/removed; corrected current source in scenarios/mysql/02-isolation/stable-snapshot.yaml, see semantic decisions A1-A10 C01058 base docs/public/ledger.jsonl:17 scenarios/mysql/02-isolation/stable-snapshot.yaml#ledger.scenario ledger-field """mysql/02-isolation/stable-snapshot.yaml""" M26 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/02-isolation/stable-snapshot.yaml#ledger.scenario at docs/public/ledger.jsonl:17 C01059 base docs/public/ledger.jsonl:17 scenarios/mysql/02-isolation/stable-snapshot.yaml#ledger.engine ledger-field """mysql""" M26 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/02-isolation/stable-snapshot.yaml#ledger.engine at docs/public/ledger.jsonl:17 C01060 base docs/public/ledger.jsonl:17 scenarios/mysql/02-isolation/stable-snapshot.yaml#ledger.product ledger-field """MySQL""" M26 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/02-isolation/stable-snapshot.yaml#ledger.product at docs/public/ledger.jsonl:17 C01061 base docs/public/ledger.jsonl:17 scenarios/mysql/02-isolation/stable-snapshot.yaml#ledger.version ledger-field """8.4.11""" M26 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/02-isolation/stable-snapshot.yaml#ledger.version at docs/public/ledger.jsonl:17 C01062 base docs/public/ledger.jsonl:17 scenarios/mysql/02-isolation/stable-snapshot.yaml#ledger.claim ledger-field """At REPEATABLE READ — MySQL's default — plain SELECTs use a single snapshot for the entire transaction: no non-repeatable reads and no phantoms.""" M26 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Replaced/removed; corrected current source in scenarios/mysql/02-isolation/stable-snapshot.yaml, see semantic decisions A1-A10 C01063 base docs/public/ledger.jsonl:17 scenarios/mysql/02-isolation/stable-snapshot.yaml#ledger.sessions ledger-field "[""A"",""B""]" M26 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/02-isolation/stable-snapshot.yaml#ledger.sessions at docs/public/ledger.jsonl:17 C01064 base docs/public/ledger.jsonl:17 scenarios/mysql/02-isolation/stable-snapshot.yaml#ledger.errors ledger-field [] M26 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/02-isolation/stable-snapshot.yaml#ledger.errors at docs/public/ledger.jsonl:17 C01065 base docs/public/ledger.jsonl:17 scenarios/mysql/02-isolation/stable-snapshot.yaml#ledger.anomaly ledger-field """P2""" M26 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/02-isolation/stable-snapshot.yaml#ledger.anomaly at docs/public/ledger.jsonl:17 C01066 base docs/public/llms-full.txt:1112 scenarios/mysql/02-isolation/stable-snapshot.yaml#llms.section.lines[1112..1175] llms-mirror Complete attributed section, lines 1112-1175; metadata and Transcript mirror for this exact schedule, source-field claims inventoried separately M26 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated mirror, same support as its exact Transcript and source fields Replaced/removed; corrected current source in scenarios/mysql/02-isolation/stable-snapshot.yaml, see semantic decisions A1-A10 C01067 base docs/mysql/02-isolation/parts/update-recheck.md:1 scenarios/mysql/02-isolation/update-recheck.yaml#Transcript.lines[1..55] generated-mirror Complete SQL/status/results, narrator paragraphs, timeline labels and verification footer, lines 1-55; claims are the exact source-field occurrences inventoried separately M27 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Demonstrated schedule mirror, not independent all-schedule evidence Retained with scoped support; current occurrence scenarios/mysql/02-isolation/update-recheck.yaml#Transcript.lines[1..55] at docs/mysql/02-isolation/parts/update-recheck.md:1 C01068 base docs/public/ledger.jsonl:18 scenarios/mysql/02-isolation/update-recheck.yaml#ledger.scenario ledger-field """mysql/02-isolation/update-recheck.yaml""" M27 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/02-isolation/update-recheck.yaml#ledger.scenario at docs/public/ledger.jsonl:18 C01069 base docs/public/ledger.jsonl:18 scenarios/mysql/02-isolation/update-recheck.yaml#ledger.engine ledger-field """mysql""" M27 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/02-isolation/update-recheck.yaml#ledger.engine at docs/public/ledger.jsonl:18 C01070 base docs/public/ledger.jsonl:18 scenarios/mysql/02-isolation/update-recheck.yaml#ledger.product ledger-field """MySQL""" M27 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/02-isolation/update-recheck.yaml#ledger.product at docs/public/ledger.jsonl:18 C01071 base docs/public/ledger.jsonl:18 scenarios/mysql/02-isolation/update-recheck.yaml#ledger.version ledger-field """8.4.11""" M27 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/02-isolation/update-recheck.yaml#ledger.version at docs/public/ledger.jsonl:18 C01072 base docs/public/ledger.jsonl:18 scenarios/mysql/02-isolation/update-recheck.yaml#ledger.claim ledger-field """An UPDATE at READ COMMITTED that waited for a lock re-evaluates its WHERE clause against the new row version — rows that no longer match are silently skipped.""" M27 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Replaced/removed; corrected current source in scenarios/mysql/02-isolation/update-recheck.yaml, see semantic decisions A1-A10 C01073 base docs/public/ledger.jsonl:18 scenarios/mysql/02-isolation/update-recheck.yaml#ledger.sessions ledger-field "[""A"",""B""]" M27 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/02-isolation/update-recheck.yaml#ledger.sessions at docs/public/ledger.jsonl:18 C01074 base docs/public/ledger.jsonl:18 scenarios/mysql/02-isolation/update-recheck.yaml#ledger.errors ledger-field [] M27 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/02-isolation/update-recheck.yaml#ledger.errors at docs/public/ledger.jsonl:18 C01075 base docs/public/llms-full.txt:1176 scenarios/mysql/02-isolation/update-recheck.yaml#llms.section.lines[1176..1234] llms-mirror Complete attributed section, lines 1176-1234; metadata and Transcript mirror for this exact schedule, source-field claims inventoried separately M27 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated mirror, same support as its exact Transcript and source fields Replaced/removed; corrected current source in scenarios/mysql/02-isolation/update-recheck.yaml, see semantic decisions A1-A10 C01076 base docs/mysql/02-isolation/parts/write-predicate-skew.md:1 scenarios/mysql/02-isolation/write-predicate-skew.yaml#Transcript.lines[1..52] generated-mirror Complete SQL/status/results, narrator paragraphs, timeline labels and verification footer, lines 1-52; claims are the exact source-field occurrences inventoried separately M28 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Demonstrated schedule mirror, not independent all-schedule evidence Replaced/removed; corrected current source in scenarios/mysql/02-isolation/write-predicate-skew.yaml, see semantic decisions A1-A10 C01077 base docs/public/ledger.jsonl:19 scenarios/mysql/02-isolation/write-predicate-skew.yaml#ledger.scenario ledger-field """mysql/02-isolation/write-predicate-skew.yaml""" M28 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/02-isolation/write-predicate-skew.yaml#ledger.scenario at docs/public/ledger.jsonl:19 C01078 base docs/public/ledger.jsonl:19 scenarios/mysql/02-isolation/write-predicate-skew.yaml#ledger.engine ledger-field """mysql""" M28 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/02-isolation/write-predicate-skew.yaml#ledger.engine at docs/public/ledger.jsonl:19 C01079 base docs/public/ledger.jsonl:19 scenarios/mysql/02-isolation/write-predicate-skew.yaml#ledger.product ledger-field """MySQL""" M28 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/02-isolation/write-predicate-skew.yaml#ledger.product at docs/public/ledger.jsonl:19 C01080 base docs/public/ledger.jsonl:19 scenarios/mysql/02-isolation/write-predicate-skew.yaml#ledger.version ledger-field """8.4.11""" M28 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/02-isolation/write-predicate-skew.yaml#ledger.version at docs/public/ledger.jsonl:19 C01081 base docs/public/ledger.jsonl:19 scenarios/mysql/02-isolation/write-predicate-skew.yaml#ledger.claim ledger-field """Under REPEATABLE READ a write's WHERE clause is evaluated against the CURRENT committed data while SELECTs keep showing the snapshot — so a transaction can \""delete every row matching X\"", delete nothing, and still see rows matching X (Hermitage's G-single write-predicate anomaly).""" M28 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Replaced/removed; corrected current source in scenarios/mysql/02-isolation/write-predicate-skew.yaml, see semantic decisions A1-A10 C01082 base docs/public/ledger.jsonl:19 scenarios/mysql/02-isolation/write-predicate-skew.yaml#ledger.sessions ledger-field "[""A"",""B""]" M28 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/02-isolation/write-predicate-skew.yaml#ledger.sessions at docs/public/ledger.jsonl:19 C01083 base docs/public/ledger.jsonl:19 scenarios/mysql/02-isolation/write-predicate-skew.yaml#ledger.errors ledger-field [] M28 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/02-isolation/write-predicate-skew.yaml#ledger.errors at docs/public/ledger.jsonl:19 C01084 base docs/public/llms-full.txt:1235 scenarios/mysql/02-isolation/write-predicate-skew.yaml#llms.section.lines[1235..1290] llms-mirror Complete attributed section, lines 1235-1290; metadata and Transcript mirror for this exact schedule, source-field claims inventoried separately M28 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated mirror, same support as its exact Transcript and source fields Replaced/removed; corrected current source in scenarios/mysql/02-isolation/write-predicate-skew.yaml, see semantic decisions A1-A10 C01085 base docs/mysql/02-isolation/parts/write-skew-rr.md:1 scenarios/mysql/02-isolation/write-skew-rr.yaml#Transcript.lines[1..59] generated-mirror Complete SQL/status/results, narrator paragraphs, timeline labels and verification footer, lines 1-59; claims are the exact source-field occurrences inventoried separately M29 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Demonstrated schedule mirror, not independent all-schedule evidence Replaced/removed; corrected current source in scenarios/mysql/02-isolation/write-skew-rr.yaml, see semantic decisions A1-A10 C01086 base docs/public/ledger.jsonl:20 scenarios/mysql/02-isolation/write-skew-rr.yaml#ledger.scenario ledger-field """mysql/02-isolation/write-skew-rr.yaml""" M29 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/02-isolation/write-skew-rr.yaml#ledger.scenario at docs/public/ledger.jsonl:20 C01087 base docs/public/ledger.jsonl:20 scenarios/mysql/02-isolation/write-skew-rr.yaml#ledger.engine ledger-field """mysql""" M29 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/02-isolation/write-skew-rr.yaml#ledger.engine at docs/public/ledger.jsonl:20 C01088 base docs/public/ledger.jsonl:20 scenarios/mysql/02-isolation/write-skew-rr.yaml#ledger.product ledger-field """MySQL""" M29 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/02-isolation/write-skew-rr.yaml#ledger.product at docs/public/ledger.jsonl:20 C01089 base docs/public/ledger.jsonl:20 scenarios/mysql/02-isolation/write-skew-rr.yaml#ledger.version ledger-field """8.4.11""" M29 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/02-isolation/write-skew-rr.yaml#ledger.version at docs/public/ledger.jsonl:20 C01090 base docs/public/ledger.jsonl:20 scenarios/mysql/02-isolation/write-skew-rr.yaml#ledger.claim ledger-field """Two REPEATABLE READ transactions can each validate an invariant against their snapshots, write to different rows, and both commit — leaving the invariant broken. This is write skew.""" M29 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Replaced/removed; corrected current source in scenarios/mysql/02-isolation/write-skew-rr.yaml, see semantic decisions A1-A10 C01091 base docs/public/ledger.jsonl:20 scenarios/mysql/02-isolation/write-skew-rr.yaml#ledger.sessions ledger-field "[""A"",""B""]" M29 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/02-isolation/write-skew-rr.yaml#ledger.sessions at docs/public/ledger.jsonl:20 C01092 base docs/public/ledger.jsonl:20 scenarios/mysql/02-isolation/write-skew-rr.yaml#ledger.errors ledger-field [] M29 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/02-isolation/write-skew-rr.yaml#ledger.errors at docs/public/ledger.jsonl:20 C01093 base docs/public/ledger.jsonl:20 scenarios/mysql/02-isolation/write-skew-rr.yaml#ledger.anomaly ledger-field """G2-item""" M29 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/02-isolation/write-skew-rr.yaml#ledger.anomaly at docs/public/ledger.jsonl:20 C01094 base docs/public/llms-full.txt:1291 scenarios/mysql/02-isolation/write-skew-rr.yaml#llms.section.lines[1291..1353] llms-mirror Complete attributed section, lines 1291-1353; metadata and Transcript mirror for this exact schedule, source-field claims inventoried separately M29 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated mirror, same support as its exact Transcript and source fields Replaced/removed; corrected current source in scenarios/mysql/02-isolation/write-skew-rr.yaml, see semantic decisions A1-A10 C01095 base docs/mysql/02-isolation/parts/write-skew-serializable.md:1 scenarios/mysql/02-isolation/write-skew-serializable.yaml#Transcript.lines[1..73] generated-mirror Complete SQL/status/results, narrator paragraphs, timeline labels and verification footer, lines 1-73; claims are the exact source-field occurrences inventoried separately M30 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Demonstrated schedule mirror, not independent all-schedule evidence Replaced/removed; corrected current source in scenarios/mysql/02-isolation/write-skew-serializable.yaml, see semantic decisions A1-A10 C01096 base docs/public/ledger.jsonl:21 scenarios/mysql/02-isolation/write-skew-serializable.yaml#ledger.scenario ledger-field """mysql/02-isolation/write-skew-serializable.yaml""" M30 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/02-isolation/write-skew-serializable.yaml#ledger.scenario at docs/public/ledger.jsonl:21 C01097 base docs/public/ledger.jsonl:21 scenarios/mysql/02-isolation/write-skew-serializable.yaml#ledger.engine ledger-field """mysql""" M30 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/02-isolation/write-skew-serializable.yaml#ledger.engine at docs/public/ledger.jsonl:21 C01098 base docs/public/ledger.jsonl:21 scenarios/mysql/02-isolation/write-skew-serializable.yaml#ledger.product ledger-field """MySQL""" M30 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/02-isolation/write-skew-serializable.yaml#ledger.product at docs/public/ledger.jsonl:21 C01099 base docs/public/ledger.jsonl:21 scenarios/mysql/02-isolation/write-skew-serializable.yaml#ledger.version ledger-field """8.4.11""" M30 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/02-isolation/write-skew-serializable.yaml#ledger.version at docs/public/ledger.jsonl:21 C01100 base docs/public/ledger.jsonl:21 scenarios/mysql/02-isolation/write-skew-serializable.yaml#ledger.claim ledger-field """Under MySQL's SERIALIZABLE, plain SELECTs take shared locks, so the write-skew interleaving deadlocks: one transaction is rolled back with errno 1213, and the invariant survives.""" M30 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Replaced/removed; corrected current source in scenarios/mysql/02-isolation/write-skew-serializable.yaml, see semantic decisions A1-A10 C01101 base docs/public/ledger.jsonl:21 scenarios/mysql/02-isolation/write-skew-serializable.yaml#ledger.sessions ledger-field "[""A"",""B""]" M30 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/02-isolation/write-skew-serializable.yaml#ledger.sessions at docs/public/ledger.jsonl:21 C01102 base docs/public/ledger.jsonl:21 scenarios/mysql/02-isolation/write-skew-serializable.yaml#ledger.errors ledger-field "[""1213""]" M30 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/02-isolation/write-skew-serializable.yaml#ledger.errors at docs/public/ledger.jsonl:21 C01103 base docs/public/ledger.jsonl:21 scenarios/mysql/02-isolation/write-skew-serializable.yaml#ledger.anomaly ledger-field """G2""" M30 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Replaced/removed; corrected current source in scenarios/mysql/02-isolation/write-skew-serializable.yaml, see semantic decisions A1-A10 C01104 base docs/public/ledger.jsonl:21 scenarios/mysql/02-isolation/write-skew-serializable.yaml#ledger.isolation ledger-field """SERIALIZABLE""" M30 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Retained with scoped support; current occurrence scenarios/mysql/02-isolation/write-skew-serializable.yaml#ledger.isolation at docs/public/ledger.jsonl:21 C01105 base docs/public/llms-full.txt:1354 scenarios/mysql/02-isolation/write-skew-serializable.yaml#llms.section.lines[1354..1430] llms-mirror Complete attributed section, lines 1354-1430; metadata and Transcript mirror for this exact schedule, source-field claims inventoried separately M30 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated mirror, same support as its exact Transcript and source fields Replaced/removed; corrected current source in scenarios/mysql/02-isolation/write-skew-serializable.yaml, see semantic decisions A1-A10 C01106 current docs/mysql/01-basics/begin-commit-rollback.md:1 docs/mysql/01-basics/begin-commit-rollback.md## BEGIN, COMMIT, ROLLBACK/line@1 lesson-unit # BEGIN, COMMIT, ROLLBACK M1 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01107 current docs/mysql/01-basics/begin-commit-rollback.md:3 docs/mysql/01-basics/begin-commit-rollback.md## BEGIN, COMMIT, ROLLBACK/paragraph@3 lesson-unit The [MySQL 8.4 autocommit contract](https://dev.mysql.com/doc/refman/8.4/en/innodb-autocommit-commit-rollback.html) starts new sessions with `autocommit=1`. A successful standalone InnoDB statement commits its transaction. `BEGIN`, an alias for `START TRANSACTION`, starts an explicit transaction that ends with COMMIT or ROLLBACK. With `autocommit=0`, transactions remain open between statements, and a new one starts after COMMIT or ROLLBACK. Drivers can issue BEGIN or change these settings, so check the actual connection. M1 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01108 current docs/mysql/01-basics/begin-commit-rollback.md:10 docs/mysql/01-basics/begin-commit-rollback.md### Autocommit and visibility/line@10 lesson-unit ## Autocommit and visibility M1 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01109 current docs/mysql/01-basics/begin-commit-rollback.md:12 docs/mysql/01-basics/begin-commit-rollback.md### Autocommit and visibility/paragraph@12 lesson-unit This MySQL 8.4.11 Scenario asserts autocommit and isolation settings. B's standalone consistent SELECT takes a new snapshot for each query and sees A's successful commit. A pre-existing REPEATABLE READ snapshot need not see a later commit, and READ UNCOMMITTED can see uncommitted changes. COMMIT does not refresh every reader's view. M1 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01110 current docs/mysql/01-basics/begin-commit-rollback.md:17 docs/mysql/01-basics/begin-commit-rollback.md### Autocommit and visibility/line@17 lesson-unit M1 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01111 current docs/mysql/01-basics/begin-commit-rollback.md:19 docs/mysql/01-basics/begin-commit-rollback.md### Duplicate-key error without IGNORE preserves the transaction {#an-error-does-not-abort-the-transaction}/line@19 lesson-unit ## Duplicate-key error without IGNORE preserves the transaction {#an-error-does-not-abort-the-transaction} M1 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01112 current docs/mysql/01-basics/begin-commit-rollback.md:21 docs/mysql/01-basics/begin-commit-rollback.md### Duplicate-key error without IGNORE preserves the transaction {#an-error-does-not-abort-the-transaction}/paragraph@21 lesson-unit The demonstrated **duplicate-key INSERT error does not abort this transaction**. The [InnoDB error-handling contract](https://dev.mysql.com/doc/refman/8.4/en/innodb-error-handling.html) documents statement rollback for duplicate-key errors without IGNORE. The Scenario asserts the earlier and later successful INSERTs after COMMIT. M1 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01113 current docs/mysql/01-basics/begin-commit-rollback.md:26 docs/mysql/01-basics/begin-commit-rollback.md### Duplicate-key error without IGNORE preserves the transaction {#an-error-does-not-abort-the-transaction}/line@26 lesson-unit M1 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01114 current docs/mysql/01-basics/begin-commit-rollback.md:28 docs/mysql/01-basics/begin-commit-rollback.md### Duplicate-key error without IGNORE preserves the transaction {#an-error-does-not-abort-the-transaction}/paragraph@28 lesson-unit Do not treat every error this way. Documented exceptions in that same manual section: M1 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01115 current docs/mysql/01-basics/begin-commit-rollback.md:30 docs/mysql/01-basics/begin-commit-rollback.md### Duplicate-key error without IGNORE preserves the transaction {#an-error-does-not-abort-the-transaction}/paragraph@30 lesson-unit - A deadlock rolls back the **entire transaction**. Start a fresh attempt, repeating reads and decisions, or return a controlled failure. - A row-lock wait timeout rolls back the **waiting statement** by default. With `innodb_rollback_on_timeout=ON`, it rolls back the entire transaction. M1 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02351 current docs/mysql/01-basics/begin-commit-rollback.md:35 docs/mysql/01-basics/begin-commit-rollback.md### Duplicate-key error without IGNORE preserves the transaction {#an-error-does-not-abort-the-transaction}/paragraph@35 lesson-unit **Entailed guarantee, by inference:** a missing COMMIT reply does not establish rollback. The [COMMIT contract](https://dev.mysql.com/doc/refman/8.4/en/commit.html) makes successful changes permanent. If COMMIT succeeds but its reply is lost, the changes remain committed; if COMMIT never reaches the server, that commit has not happened. The missing reply alone cannot distinguish these cases. After connection loss, reconnect and determine the outcome before repeating the work. No Transcript here demonstrates a network failure. M1 MySQL 8.4, InnoDB COMMIT; client receives no reply; two conditional communication outcomes, not a crash/durability experiment Entailed guarantee: explicit inference from MySQL 8.4 section 15.3.1 COMMIT contract; reply lost after successful commit versus COMMIT never reaching server. No network-failure execution. Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01116 current docs/mysql/01-basics/begin-commit-rollback.md:43 docs/mysql/01-basics/begin-commit-rollback.md### Duplicate-key error without IGNORE preserves the transaction {#an-error-does-not-abort-the-transaction}/paragraph@43 lesson-unit If the application abandons an open transaction after a statement error, explicitly ROLLBACK. Continuing to COMMIT can retain earlier changes. A savepoint can discard a [multi-statement branch](/mysql/01-basics/savepoints), but cannot recover a transaction already rolled back by a deadlock. PostgreSQL's [failed explicit-transaction example](/postgres/01-basics/begin-commit-rollback) has a different error state and savepoint recovery path. M1 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01117 current docs/mysql/01-basics/begin-commit-rollback.md:50 docs/mysql/01-basics/begin-commit-rollback.md### Implicit transaction boundaries/line@50 lesson-unit ## Implicit transaction boundaries M1 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01118 current docs/mysql/01-basics/begin-commit-rollback.md:52 docs/mysql/01-basics/begin-commit-rollback.md### Implicit transaction boundaries/paragraph@52 lesson-unit The [MySQL 8.4 implicit-commit list](https://dev.mysql.com/doc/refman/8.4/en/implicit-commit.html) includes ALTER TABLE and CREATE INDEX, which commit preceding work before running. START TRANSACTION also commits an existing transaction: transactions do not nest. CREATE TEMPORARY TABLE and DROP TEMPORARY TABLE do not implicitly commit, but their creation or removal cannot be rolled back. These are Documented contracts, not SQL executed in the two Transcripts above. See the [DDL example](/mysql/05-patterns/orm-pitfalls) for the existing index-build Scenario. M1 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01119 current docs/mysql/01-basics/begin-commit-rollback.md:60 docs/mysql/01-basics/begin-commit-rollback.md### Further reading/line@60 lesson-unit ## Further reading M1 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01120 current docs/mysql/01-basics/begin-commit-rollback.md:62 docs/mysql/01-basics/begin-commit-rollback.md### Further reading/paragraph@62 lesson-unit - [MySQL 8.4: START TRANSACTION, COMMIT, and ROLLBACK](https://dev.mysql.com/doc/refman/8.4/en/commit.html) - [The same lesson on PostgreSQL](/postgres/01-basics/begin-commit-rollback) M1 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01121 current docs/mysql/01-basics/savepoints.md:1 docs/mysql/01-basics/savepoints.md## Savepoints/line@1 lesson-unit # Savepoints M2 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01122 current docs/mysql/01-basics/savepoints.md:3 docs/mysql/01-basics/savepoints.md## Savepoints/paragraph@3 lesson-unit The [MySQL 8.4 savepoint contract](https://dev.mysql.com/doc/refman/8.4/en/savepoint.html) defines a named point inside a transaction. ROLLBACK TO SAVEPOINT undoes subsequent InnoDB row changes without ending that transaction. It does not commit earlier work. The examples run on MySQL 8.4.11, InnoDB, with explicit BEGIN. M2 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01123 current docs/mysql/01-basics/savepoints.md:8 docs/mysql/01-basics/savepoints.md### Discard a risky branch/line@8 lesson-unit ## Discard a risky branch M2 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01124 current docs/mysql/01-basics/savepoints.md:10 docs/mysql/01-basics/savepoints.md### Discard a risky branch/paragraph@10 lesson-unit The duplicate-key error rolls back one INSERT, but the preceding branch INSERT survives until A rolls back to the savepoint. The intermediate SELECT asserts that the branch row is gone and the earlier INSERT remains. A then commits a replacement. M2 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01125 current docs/mysql/01-basics/savepoints.md:14 docs/mysql/01-basics/savepoints.md### Discard a risky branch/line@14 lesson-unit M2 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01126 current docs/mysql/01-basics/savepoints.md:16 docs/mysql/01-basics/savepoints.md### Nesting and RELEASE/line@16 lesson-unit ## Nesting and RELEASE M2 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01127 current docs/mysql/01-basics/savepoints.md:18 docs/mysql/01-basics/savepoints.md### Nesting and RELEASE/paragraph@18 lesson-unit The second Scenario asserts that rolling back to the outer savepoint destroys the inner one (1305). RELEASE removes the outer bookmark without undoing row 4, and an attempt to reuse it also fails with 1305. The final committed rows are 1 and 4. M2 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01128 current docs/mysql/01-basics/savepoints.md:22 docs/mysql/01-basics/savepoints.md### Nesting and RELEASE/line@22 lesson-unit M2 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01129 current docs/mysql/01-basics/savepoints.md:24 docs/mysql/01-basics/savepoints.md### Nesting and RELEASE/paragraph@24 lesson-unit The manual additionally documents that COMMIT and full ROLLBACK delete savepoints, and reusing a savepoint name replaces the old point. Savepoint rollback does **not** generally release row locks stored in memory after the savepoint. An inserted row's lock carried in its transaction ID is released when that insertion is undone. Those lock and same-name rules are Documented contracts, not asserted by these INSERT-only schedules. Do not infer that a discarded branch releases every lock. M2 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01130 current docs/mysql/01-basics/savepoints.md:31 docs/mysql/01-basics/savepoints.md### Nesting and RELEASE/paragraph@31 lesson-unit Statement recovery is error-specific. A deadlock rolls back the whole transaction, including its savepoints; see [error handling](/mysql/01-basics/begin-commit-rollback). Nontransactional writes and implicit-commit DDL are outside this rollback promise. M2 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01131 current docs/mysql/01-basics/savepoints.md:35 docs/mysql/01-basics/savepoints.md### Further reading/line@35 lesson-unit ## Further reading M2 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01132 current docs/mysql/01-basics/savepoints.md:37 docs/mysql/01-basics/savepoints.md### Further reading/paragraph@37 lesson-unit - [MySQL 8.4: SAVEPOINT, ROLLBACK TO SAVEPOINT, and RELEASE SAVEPOINT](https://dev.mysql.com/doc/refman/8.4/en/savepoint.html) - [The same lesson on PostgreSQL](/postgres/01-basics/savepoints) M2 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01133 current docs/mysql/01-basics/what-is-a-transaction.md:1 docs/mysql/01-basics/what-is-a-transaction.md## What is a transaction?/line@1 lesson-unit # What is a transaction? M3 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01134 current docs/mysql/01-basics/what-is-a-transaction.md:3 docs/mysql/01-basics/what-is-a-transaction.md## What is a transaction?/paragraph@3 lesson-unit A transaction groups transactional table changes so that COMMIT retains them and ROLLBACK discards them. This chapter uses **InnoDB on MySQL 8.4.11**, with `autocommit=1` and REPEATABLE READ unless a Scenario sets another level. These are table-write examples, not crash, network, or external-effect tests. M3 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01135 current docs/mysql/01-basics/what-is-a-transaction.md:8 docs/mysql/01-basics/what-is-a-transaction.md## What is a transaction?/paragraph@8 lesson-unit The [MySQL 8.4 transaction manual](https://dev.mysql.com/doc/refman/8.4/en/commit.html) documents these boundaries. Nontransactional tables such as MyISAM cannot have their writes undone by ROLLBACK. DDL can cause an [implicit commit](https://dev.mysql.com/doc/refman/8.4/en/implicit-commit.html), so not every SQL operation belongs to the rollback boundary. M3 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01136 current docs/mysql/01-basics/what-is-a-transaction.md:14 docs/mysql/01-basics/what-is-a-transaction.md## What is a transaction?/line@14 lesson-unit ::: tip How to read the demos M3 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01137 current docs/mysql/01-basics/what-is-a-transaction.md:15 docs/mysql/01-basics/what-is-a-transaction.md## What is a transaction?/paragraph@15 lesson-unit Each Transcript and timeline comes from its linked Scenario. **Demonstrated behavior** means the schedule executes and asserts that result. A broader **Documented contract** needs the cited MySQL 8.4 manual; an **Entailed guarantee** is marked and explained. One schedule does not prove all schedules. See [methodology](/about/methodology). M3 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Entailed where marked, derivation and contracts in the named section; D/M separately identified Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01138 current docs/mysql/01-basics/what-is-a-transaction.md:19 docs/mysql/01-basics/what-is-a-transaction.md## What is a transaction?/line@19 lesson-unit ::: M3 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01139 current docs/mysql/01-basics/what-is-a-transaction.md:21 docs/mysql/01-basics/what-is-a-transaction.md### Atomicity, demonstrated/line@21 lesson-unit ## Atomicity, demonstrated M3 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01140 current docs/mysql/01-basics/what-is-a-transaction.md:23 docs/mysql/01-basics/what-is-a-transaction.md### Atomicity, demonstrated/paragraph@23 lesson-unit A credits bob by 150, then attempts to debit alice, who has only 100. The CHECK error rolls back the failed debit statement. A's own SELECT still sees bob's credit. Only A's explicit ROLLBACK discards that earlier successful change. B's standalone consistent SELECTs see the original balances before and after rollback. M3 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01141 current docs/mysql/01-basics/what-is-a-transaction.md:28 docs/mysql/01-basics/what-is-a-transaction.md### Atomicity, demonstrated/line@28 lesson-unit M3 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01142 current docs/mysql/01-basics/what-is-a-transaction.md:30 docs/mysql/01-basics/what-is-a-transaction.md### Atomicity, demonstrated/paragraph@30 lesson-unit The error did not itself undo the transaction. The [next lesson](/mysql/01-basics/begin-commit-rollback) distinguishes statement errors from errors that roll back the whole transaction. Visibility also depends on the [reader's isolation level and operation](/mysql/02-isolation/snapshots-and-the-four-levels); READ UNCOMMITTED can expose another transaction's uncommitted changes. M3 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01143 current docs/mysql/01-basics/what-is-a-transaction.md:36 docs/mysql/01-basics/what-is-a-transaction.md### Further reading/line@36 lesson-unit ## Further reading M3 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01144 current docs/mysql/01-basics/what-is-a-transaction.md:38 docs/mysql/01-basics/what-is-a-transaction.md### Further reading/paragraph@38 lesson-unit - [MySQL 8.4: InnoDB and the ACID Model](https://dev.mysql.com/doc/refman/8.4/en/mysql-acid.html) - [Concepts: what is a transaction?](/concepts/what-is-a-transaction) - [The same lesson on PostgreSQL](/postgres/01-basics/what-is-a-transaction) M3 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01145 current docs/mysql/02-isolation/anomaly-catalog.md:1 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/line@1 lesson-unit # The anomaly catalog M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01146 current docs/mysql/02-isolation/anomaly-catalog.md:3 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/paragraph@3 lesson-unit This catalog distinguishes executed schedules on **MySQL 8.4.11, InnoDB** from broader [MySQL 8.4 contracts](https://dev.mysql.com/doc/refman/8.4/en/innodb-transaction-isolation-levels.html). The [concept catalog](/concepts/isolation-anomalies) defines the names. The examples concern transactional table rows, with isolation and transaction boundaries shown in their SQL. They do not establish full Hermitage coverage. M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01147 current docs/mysql/02-isolation/anomaly-catalog.md:9 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/paragraph@9 lesson-unit **D** means Demonstrated behavior: the linked Scenario executes and asserts that particular schedule, not all schedules. **M** means a Documented contract in the named manual sections below. **†** means an Entailed guarantee without a direct execution at that level, with its derivation in [How to use this table](#how-to-use-this-table). Own writes, mixed current/snapshot reads, and nontransactional effects need separate scope. M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Entailed where marked, derivation and contracts in the named section; D/M separately identified Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01148 current docs/mysql/02-isolation/anomaly-catalog.md:15 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@15.cell[0] catalog-cell Code M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01149 current docs/mysql/02-isolation/anomaly-catalog.md:15 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@15.cell[1] catalog-cell Anomaly or operation M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01150 current docs/mysql/02-isolation/anomaly-catalog.md:15 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@15.cell[2] catalog-cell READ UNCOMMITTED M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01151 current docs/mysql/02-isolation/anomaly-catalog.md:15 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@15.cell[3] catalog-cell READ COMMITTED M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01152 current docs/mysql/02-isolation/anomaly-catalog.md:15 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@15.cell[4] catalog-cell REPEATABLE READ, default M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02328 current docs/mysql/02-isolation/anomaly-catalog.md:15 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@15.cell[5] catalog-cell SERIALIZABLE M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01153 current docs/mysql/02-isolation/anomaly-catalog.md:16 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@16.cell[0] catalog-cell --- M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01154 current docs/mysql/02-isolation/anomaly-catalog.md:16 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@16.cell[1] catalog-cell --- M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01155 current docs/mysql/02-isolation/anomaly-catalog.md:16 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@16.cell[2] catalog-cell --- M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01156 current docs/mysql/02-isolation/anomaly-catalog.md:16 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@16.cell[3] catalog-cell --- M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01157 current docs/mysql/02-isolation/anomaly-catalog.md:16 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@16.cell[4] catalog-cell --- M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02329 current docs/mysql/02-isolation/anomaly-catalog.md:16 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@16.cell[5] catalog-cell --- M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01158 current docs/mysql/02-isolation/anomaly-catalog.md:17 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@17.cell[0] catalog-cell G0 M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01159 current docs/mysql/02-isolation/anomaly-catalog.md:17 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@17.cell[1] catalog-cell Overwrite before the prior writer ends M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01160 current docs/mysql/02-isolation/anomaly-catalog.md:17 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@17.cell[2] catalog-cell D: [second writer waits](#dirty-writes-g0); † M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Entailed where marked, derivation and contracts in the named section; D/M separately identified Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01161 current docs/mysql/02-isolation/anomaly-catalog.md:17 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@17.cell[3] catalog-cell † row locks M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Entailed where marked, derivation and contracts in the named section; D/M separately identified Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01162 current docs/mysql/02-isolation/anomaly-catalog.md:17 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@17.cell[4] catalog-cell † row locks M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Entailed where marked, derivation and contracts in the named section; D/M separately identified Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02330 current docs/mysql/02-isolation/anomaly-catalog.md:17 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@17.cell[5] catalog-cell † row locks M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Entailed where marked, derivation and contracts in the named section; D/M separately identified Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01163 current docs/mysql/02-isolation/anomaly-catalog.md:18 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@18.cell[0] catalog-cell G1a M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01164 current docs/mysql/02-isolation/anomaly-catalog.md:18 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@18.cell[1] catalog-cell Dirty read of a concurrent table change M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01165 current docs/mysql/02-isolation/anomaly-catalog.md:18 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@18.cell[2] catalog-cell D: [999 then rollback](/mysql/02-isolation/snapshots-and-the-four-levels#read-uncommitted-means-it) M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01166 current docs/mysql/02-isolation/anomaly-catalog.md:18 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@18.cell[3] catalog-cell M: excluded M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01167 current docs/mysql/02-isolation/anomaly-catalog.md:18 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@18.cell[4] catalog-cell M: excluded M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02331 current docs/mysql/02-isolation/anomaly-catalog.md:18 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@18.cell[5] catalog-cell M: excluded M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01168 current docs/mysql/02-isolation/anomaly-catalog.md:19 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@19.cell[0] catalog-cell G1b M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01169 current docs/mysql/02-isolation/anomaly-catalog.md:19 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@19.cell[1] catalog-cell Intermediate read M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01170 current docs/mysql/02-isolation/anomaly-catalog.md:19 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@19.cell[2] catalog-cell D: [draft 999](#intermediate-reads-g1b) M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01171 current docs/mysql/02-isolation/anomaly-catalog.md:19 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@19.cell[3] catalog-cell D: [draft 555 excluded](#intermediate-reads-g1b); † M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Entailed where marked, derivation and contracts in the named section; D/M separately identified Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01172 current docs/mysql/02-isolation/anomaly-catalog.md:19 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@19.cell[4] catalog-cell † M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Entailed where marked, derivation and contracts in the named section; D/M separately identified Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02332 current docs/mysql/02-isolation/anomaly-catalog.md:19 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@19.cell[5] catalog-cell † M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Entailed where marked, derivation and contracts in the named section; D/M separately identified Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01173 current docs/mysql/02-isolation/anomaly-catalog.md:20 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@20.cell[0] catalog-cell G1c M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01174 current docs/mysql/02-isolation/anomaly-catalog.md:20 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@20.cell[1] catalog-cell Cycle through dirty cross-reads M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01175 current docs/mysql/02-isolation/anomaly-catalog.md:20 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@20.cell[2] catalog-cell D: [both new values, both commit](#circular-information-flow-g1c) M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01176 current docs/mysql/02-isolation/anomaly-catalog.md:20 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@20.cell[3] catalog-cell D: [old values](#circular-information-flow-g1c); † dirty cycle excluded M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Entailed where marked, derivation and contracts in the named section; D/M separately identified Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01177 current docs/mysql/02-isolation/anomaly-catalog.md:20 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@20.cell[4] catalog-cell † dirty cycle excluded M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Entailed where marked, derivation and contracts in the named section; D/M separately identified Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02333 current docs/mysql/02-isolation/anomaly-catalog.md:20 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@20.cell[5] catalog-cell † dirty cycle excluded M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Entailed where marked, derivation and contracts in the named section; D/M separately identified Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01178 current docs/mysql/02-isolation/anomaly-catalog.md:21 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@21.cell[0] catalog-cell OTV M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01179 current docs/mysql/02-isolation/anomaly-catalog.md:21 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@21.cell[1] catalog-cell Committed rows hidden by an uncommitted overwrite M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01180 current docs/mysql/02-isolation/anomaly-catalog.md:21 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@21.cell[2] catalog-cell D: [12/19 split view](#observed-transaction-vanishes-otv) M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01181 current docs/mysql/02-isolation/anomaly-catalog.md:21 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@21.cell[3] catalog-cell D: [draft excluded](#observed-transaction-vanishes-otv); † M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Entailed where marked, derivation and contracts in the named section; D/M separately identified Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01182 current docs/mysql/02-isolation/anomaly-catalog.md:21 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@21.cell[4] catalog-cell † M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Entailed where marked, derivation and contracts in the named section; D/M separately identified Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02334 current docs/mysql/02-isolation/anomaly-catalog.md:21 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@21.cell[5] catalog-cell † M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Entailed where marked, derivation and contracts in the named section; D/M separately identified Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01183 current docs/mysql/02-isolation/anomaly-catalog.md:22 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@22.cell[0] catalog-cell P2 M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01184 current docs/mysql/02-isolation/anomaly-catalog.md:22 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@22.cell[1] catalog-cell Non-repeatable consistent SELECT from concurrent commit M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01185 current docs/mysql/02-isolation/anomaly-catalog.md:22 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@22.cell[2] catalog-cell Not executed here M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01186 current docs/mysql/02-isolation/anomaly-catalog.md:22 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@22.cell[3] catalog-cell D: [100 then 200](/mysql/02-isolation/read-committed#non-repeatable-reads) M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01187 current docs/mysql/02-isolation/anomaly-catalog.md:22 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@22.cell[4] catalog-cell M: excluded; D: [stable values](/mysql/02-isolation/repeatable-read#one-snapshot-no-phantoms) M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02335 current docs/mysql/02-isolation/anomaly-catalog.md:22 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@22.cell[5] catalog-cell M: excluded in one transaction M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01188 current docs/mysql/02-isolation/anomaly-catalog.md:23 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@23.cell[0] catalog-cell G-single M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01189 current docs/mysql/02-isolation/anomaly-catalog.md:23 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@23.cell[1] catalog-cell Read skew across separate consistent SELECTs M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01190 current docs/mysql/02-isolation/anomaly-catalog.md:23 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@23.cell[2] catalog-cell Not executed here M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01191 current docs/mysql/02-isolation/anomaly-catalog.md:23 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@23.cell[3] catalog-cell D: [125 total](/mysql/02-isolation/read-committed#read-skew-a-total-that-never-existed) M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01192 current docs/mysql/02-isolation/anomaly-catalog.md:23 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@23.cell[4] catalog-cell D: [100 total](/mysql/02-isolation/read-committed#read-skew-a-total-that-never-existed); † consistent reads; D: [mixed DELETE/SELECT](/mysql/02-isolation/repeatable-read#your-delete-and-your-select-live-in-different-worlds) M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Entailed where marked, derivation and contracts in the named section; D/M separately identified Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02336 current docs/mysql/02-isolation/anomaly-catalog.md:23 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@23.cell[5] catalog-cell † participating transaction M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Entailed where marked, derivation and contracts in the named section; D/M separately identified Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01193 current docs/mysql/02-isolation/anomaly-catalog.md:24 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@24.cell[0] catalog-cell PMP M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01194 current docs/mysql/02-isolation/anomaly-catalog.md:24 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@24.cell[1] catalog-cell Phantom from concurrent commit M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01195 current docs/mysql/02-isolation/anomaly-catalog.md:24 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@24.cell[2] catalog-cell Not executed here M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01196 current docs/mysql/02-isolation/anomaly-catalog.md:24 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@24.cell[3] catalog-cell D: [new matching row](/mysql/02-isolation/read-committed#phantoms) M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01197 current docs/mysql/02-isolation/anomaly-catalog.md:24 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@24.cell[4] catalog-cell M: excluded for consistent SELECTs; M: current DML can reach post-snapshot rows M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02337 current docs/mysql/02-isolation/anomaly-catalog.md:24 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@24.cell[5] catalog-cell † locking range in one transaction M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01198 current docs/mysql/02-isolation/anomaly-catalog.md:25 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@25.cell[0] catalog-cell P4 M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01199 current docs/mysql/02-isolation/anomaly-catalog.md:25 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@25.cell[1] catalog-cell In-transaction read-modify-write M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01200 current docs/mysql/02-isolation/anomaly-catalog.md:25 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@25.cell[2] catalog-cell Not executed here M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01201 current docs/mysql/02-isolation/anomaly-catalog.md:25 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@25.cell[3] catalog-cell D: [110 instead of 120](/mysql/02-isolation/lost-update#at-read-committed) M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01202 current docs/mysql/02-isolation/anomaly-catalog.md:25 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@25.cell[4] catalog-cell D: [110 instead of 120](/mysql/02-isolation/lost-update#repeatable-read-does-not-save-you) M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02338 current docs/mysql/02-isolation/anomaly-catalog.md:25 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@25.cell[5] catalog-cell † retained read locks; not executed here M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01203 current docs/mysql/02-isolation/anomaly-catalog.md:26 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@26.cell[0] catalog-cell G2-item M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01204 current docs/mysql/02-isolation/anomaly-catalog.md:26 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@26.cell[1] catalog-cell On-call count and separate-row writes M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01205 current docs/mysql/02-isolation/anomaly-catalog.md:26 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@26.cell[2] catalog-cell Not executed here M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01206 current docs/mysql/02-isolation/anomaly-catalog.md:26 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@26.cell[3] catalog-cell Not executed here M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01207 current docs/mysql/02-isolation/anomaly-catalog.md:26 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@26.cell[4] catalog-cell D: [both commit, count zero](/mysql/02-isolation/serializable#write-skew-at-repeatable-read) M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02339 current docs/mysql/02-isolation/anomaly-catalog.md:26 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@26.cell[5] catalog-cell D: [B rejected, count one](/mysql/02-isolation/serializable#serializable-stops-it-with-locks); † rule protection M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01208 current docs/mysql/02-isolation/anomaly-catalog.md:27 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@27.cell[0] catalog-cell G2 M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01209 current docs/mysql/02-isolation/anomaly-catalog.md:27 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@27.cell[1] catalog-cell Predicate serialization anomaly beyond this on-call schedule M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01210 current docs/mysql/02-isolation/anomaly-catalog.md:27 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@27.cell[2] catalog-cell Not executed here M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01211 current docs/mysql/02-isolation/anomaly-catalog.md:27 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@27.cell[3] catalog-cell Not executed here M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01212 current docs/mysql/02-isolation/anomaly-catalog.md:27 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@27.cell[4] catalog-cell Not executed here; M: snapshot and current reads differ M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02340 current docs/mysql/02-isolation/anomaly-catalog.md:27 docs/mysql/02-isolation/anomaly-catalog.md## The anomaly catalog/table.row@27.cell[5] catalog-cell † locking ranges for participating transactions; no predicate schedule here M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01213 current docs/mysql/02-isolation/anomaly-catalog.md:29 docs/mysql/02-isolation/anomaly-catalog.md### How to use this table/line@29 lesson-unit ## How to use this table M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Entailed where marked, derivation and contracts in the named section; D/M separately identified Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01214 current docs/mysql/02-isolation/anomaly-catalog.md:31 docs/mysql/02-isolation/anomaly-catalog.md### How to use this table/paragraph@31 lesson-unit The M cells use MySQL 8.4's [level descriptions](https://dev.mysql.com/doc/refman/8.4/en/innodb-transaction-isolation-levels.html) and [consistent-read contract](https://dev.mysql.com/doc/refman/8.4/en/innodb-consistent-read.html). READ COMMITTED and REPEATABLE READ consistent SELECTs exclude concurrent uncommitted versions, while own earlier writes remain visible. REPEATABLE READ retains the first consistent-read snapshot. Current UPDATE, DELETE and locking reads use different visibility. None of those rules makes every statement a snapshot read. M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Entailed where marked, derivation and contracts in the named section; D/M separately identified Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01215 current docs/mysql/02-isolation/anomaly-catalog.md:38 docs/mysql/02-isolation/anomaly-catalog.md### How to use this table/paragraph@38 lesson-unit The † cells are explicit derivations, not executions at every level: M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Entailed where marked, derivation and contracts in the named section; D/M separately identified Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01216 current docs/mysql/02-isolation/anomaly-catalog.md:40 docs/mysql/02-isolation/anomaly-catalog.md### How to use this table/paragraph@40 lesson-unit - G0: the [exclusive locks on UPDATE targets](https://dev.mysql.com/doc/refman/8.4/en/innodb-locks-set.html) prevent a second writer overwriting an uncommitted target. This does not prevent every dependency cycle or define dirty writes by a mixed final state. - G1b and dirty-read G1c: excluding uncommitted versions excludes intermediate drafts and the dirty cross-reads that form this cycle. It does not exclude every read/write dependency cycle at READ COMMITTED; both old reads can still lack a serial order. - OTV: a consistent read selects committed versions, so an uncommitted overwrite cannot hide the preceding committed version. Separate READ COMMITTED statements have different snapshots; a later committed partial overwrite can change one row. - Read skew: one REPEATABLE READ snapshot excludes intervening concurrent commits between consistent SELECTs when the reader does not modify the observed data. SERIALIZABLE retained shared locks likewise prevent a writer from invalidating those reads before the transaction ends. - SERIALIZABLE PMP, P4, and G2: [locking reads](https://dev.mysql.com/doc/refman/8.4/en/innodb-locking-reads.html) retain shared locks in the explicit transaction, and the [index-range rules](https://dev.mysql.com/doc/refman/8.4/en/innodb-locks-set.html) protect scanned predicates against conflicting changes/inserts. Competing writes must wait or an attempt must fail rather than both silently invalidating the protected decisions. Every relevant operation must be inside the participating transaction; standalone autocommit reads do not retain this protection. A business rule additionally requires each serial transaction to preserve it. M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Entailed where marked, derivation and contracts in the named section; D/M separately identified Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01217 current docs/mysql/02-isolation/anomaly-catalog.md:62 docs/mysql/02-isolation/anomaly-catalog.md### How to use this table/paragraph@62 lesson-unit The [SERIALIZABLE Scenario](/mysql/02-isolation/serializable) demonstrates both explicit BEGIN locking and the standalone autocommit exception. It does not execute every predicate schedule, prove all catalog cells by repetition, or test stale reads made outside a protected transaction. A schedule's absence in one run is not impossibility. M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Entailed where marked, derivation and contracts in the named section; D/M separately identified Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01218 current docs/mysql/02-isolation/anomaly-catalog.md:67 docs/mysql/02-isolation/anomaly-catalog.md### The MySQL-specific pattern/line@67 lesson-unit ## The MySQL-specific pattern M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01219 current docs/mysql/02-isolation/anomaly-catalog.md:69 docs/mysql/02-isolation/anomaly-catalog.md### The MySQL-specific pattern/paragraph@69 lesson-unit REPEATABLE READ consistent SELECTs exclude later concurrent commits, but current DML and own writes can change what the transaction subsequently sees. The [lost-update examples](/mysql/02-isolation/lost-update) commit stale literal writes at both READ COMMITTED and REPEATABLE READ. This does not mean isolation can never protect a read-modify-write operation: explicit SERIALIZABLE transactions lock reads. Choose a protection with the transaction boundary and writer participation stated. M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01220 current docs/mysql/02-isolation/anomaly-catalog.md:76 docs/mysql/02-isolation/anomaly-catalog.md### What READ UNCOMMITTED really costs/line@76 lesson-unit ## What READ UNCOMMITTED really costs M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01221 current docs/mysql/02-isolation/anomaly-catalog.md:78 docs/mysql/02-isolation/anomaly-catalog.md### What READ UNCOMMITTED really costs/paragraph@78 lesson-unit These schedules demonstrate particular dirty reads and a blocked competing write. The all-level exclusions above use contracts and marked derivations separately. M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01222 current docs/mysql/02-isolation/anomaly-catalog.md:81 docs/mysql/02-isolation/anomaly-catalog.md#### Dirty writes (G0)/line@81 lesson-unit ### Dirty writes (G0) M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01223 current docs/mysql/02-isolation/anomaly-catalog.md:83 docs/mysql/02-isolation/anomaly-catalog.md#### Dirty writes (G0)/paragraph@83 lesson-unit B's first UPDATE waits for A to commit. Both of B's final prices are asserted in this order of execution. An uncommitted overwrite is the dirty-write event; interleaving or a mixed final state alone is not its definition. M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01224 current docs/mysql/02-isolation/anomaly-catalog.md:87 docs/mysql/02-isolation/anomaly-catalog.md#### Dirty writes (G0)/line@87 lesson-unit M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01225 current docs/mysql/02-isolation/anomaly-catalog.md:89 docs/mysql/02-isolation/anomaly-catalog.md#### Intermediate reads (G1b)/line@89 lesson-unit ### Intermediate reads (G1b) M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01226 current docs/mysql/02-isolation/anomaly-catalog.md:91 docs/mysql/02-isolation/anomaly-catalog.md#### Intermediate reads (G1b)/paragraph@91 lesson-unit B reads draft 999 at READ UNCOMMITTED before A replaces it with committed 110. In the READ COMMITTED repeat, B reads 110 while A's draft 555 is uncommitted. This repeat does not claim to read 100 and then 110 at READ COMMITTED. M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01227 current docs/mysql/02-isolation/anomaly-catalog.md:95 docs/mysql/02-isolation/anomaly-catalog.md#### Intermediate reads (G1b)/line@95 lesson-unit M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01228 current docs/mysql/02-isolation/anomaly-catalog.md:97 docs/mysql/02-isolation/anomaly-catalog.md#### Circular information flow (G1c)/line@97 lesson-unit ### Circular information flow (G1c) M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01229 current docs/mysql/02-isolation/anomaly-catalog.md:99 docs/mysql/02-isolation/anomaly-catalog.md#### Circular information flow (G1c)/paragraph@99 lesson-unit At READ UNCOMMITTED, both read the other's uncommitted new value and both commit: neither serial order produces both observations. After resetting the balances, READ COMMITTED excludes those dirty values. Both see 100 and both commit, a different dependency cycle that is still not serial-equivalent. No serializability claim is made for READ COMMITTED. M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01230 current docs/mysql/02-isolation/anomaly-catalog.md:105 docs/mysql/02-isolation/anomaly-catalog.md#### Circular information flow (G1c)/line@105 lesson-unit M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01231 current docs/mysql/02-isolation/anomaly-catalog.md:107 docs/mysql/02-isolation/anomaly-catalog.md#### Observed transaction vanishes (OTV)/line@107 lesson-unit ### Observed transaction vanishes (OTV) M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01232 current docs/mysql/02-isolation/anomaly-catalog.md:109 docs/mysql/02-isolation/anomaly-catalog.md#### Observed transaction vanishes (OTV)/paragraph@109 lesson-unit C's READ UNCOMMITTED SELECT returns 12 from B's draft and 19 from A's commit. The READ COMMITTED repeat excludes A's uncommitted 51/59, then includes both after commit. These returned rows illustrate the stated split-view operation; the project does not claim the complete formal Hermitage suite or permanent visibility of a committed transaction's original values. M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01233 current docs/mysql/02-isolation/anomaly-catalog.md:115 docs/mysql/02-isolation/anomaly-catalog.md#### Observed transaction vanishes (OTV)/line@115 lesson-unit M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01234 current docs/mysql/02-isolation/anomaly-catalog.md:117 docs/mysql/02-isolation/anomaly-catalog.md### Error codes to retry on/line@117 lesson-unit ## Error codes to retry on M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01235 current docs/mysql/02-isolation/anomaly-catalog.md:119 docs/mysql/02-isolation/anomaly-catalog.md### Error codes to retry on/paragraph@119 lesson-unit The [InnoDB error-handling contract](https://dev.mysql.com/doc/refman/8.4/en/innodb-error-handling.html) distinguishes rollback scope. Do not retry based on a code without checking the transaction state and application decision. M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01236 current docs/mysql/02-isolation/anomaly-catalog.md:123 docs/mysql/02-isolation/anomaly-catalog.md### Error codes to retry on/table.row@123.cell[0] catalog-cell errno M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01237 current docs/mysql/02-isolation/anomaly-catalog.md:123 docs/mysql/02-isolation/anomaly-catalog.md### Error codes to retry on/table.row@123.cell[1] catalog-cell SQLSTATE M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01238 current docs/mysql/02-isolation/anomaly-catalog.md:123 docs/mysql/02-isolation/anomaly-catalog.md### Error codes to retry on/table.row@123.cell[2] catalog-cell Scope and next action M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02341 current docs/mysql/02-isolation/anomaly-catalog.md:123 docs/mysql/02-isolation/anomaly-catalog.md### Error codes to retry on/table.row@123.cell[3] catalog-cell Evidence M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01239 current docs/mysql/02-isolation/anomaly-catalog.md:124 docs/mysql/02-isolation/anomaly-catalog.md### Error codes to retry on/table.row@124.cell[0] catalog-cell --- M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01240 current docs/mysql/02-isolation/anomaly-catalog.md:124 docs/mysql/02-isolation/anomaly-catalog.md### Error codes to retry on/table.row@124.cell[1] catalog-cell --- M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01241 current docs/mysql/02-isolation/anomaly-catalog.md:124 docs/mysql/02-isolation/anomaly-catalog.md### Error codes to retry on/table.row@124.cell[2] catalog-cell --- M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02342 current docs/mysql/02-isolation/anomaly-catalog.md:124 docs/mysql/02-isolation/anomaly-catalog.md### Error codes to retry on/table.row@124.cell[3] catalog-cell --- M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01242 current docs/mysql/02-isolation/anomaly-catalog.md:125 docs/mysql/02-isolation/anomaly-catalog.md### Error codes to retry on/table.row@125.cell[0] catalog-cell 1213 M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01243 current docs/mysql/02-isolation/anomaly-catalog.md:125 docs/mysql/02-isolation/anomaly-catalog.md### Error codes to retry on/table.row@125.cell[1] catalog-cell 40001 M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01244 current docs/mysql/02-isolation/anomaly-catalog.md:125 docs/mysql/02-isolation/anomaly-catalog.md### Error codes to retry on/table.row@125.cell[2] catalog-cell Entire transaction rolled back; retry fresh reads/decisions or return controlled failure M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02343 current docs/mysql/02-isolation/anomaly-catalog.md:125 docs/mysql/02-isolation/anomaly-catalog.md### Error codes to retry on/table.row@125.cell[3] catalog-cell D: [SERIALIZABLE schedule](/mysql/02-isolation/serializable); M: error handling M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01245 current docs/mysql/02-isolation/anomaly-catalog.md:126 docs/mysql/02-isolation/anomaly-catalog.md### Error codes to retry on/table.row@126.cell[0] catalog-cell 1205 M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01246 current docs/mysql/02-isolation/anomaly-catalog.md:126 docs/mysql/02-isolation/anomaly-catalog.md### Error codes to retry on/table.row@126.cell[1] catalog-cell HY000 M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01247 current docs/mysql/02-isolation/anomaly-catalog.md:126 docs/mysql/02-isolation/anomaly-catalog.md### Error codes to retry on/table.row@126.cell[2] catalog-cell Waiting statement rolled back by default; entire transaction with innodb_rollback_on_timeout=ON M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02344 current docs/mysql/02-isolation/anomaly-catalog.md:126 docs/mysql/02-isolation/anomaly-catalog.md### Error codes to retry on/table.row@126.cell[3] catalog-cell M: error handling; separate [locking lesson](/mysql/03-locking/nowait-skip-locked) M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01248 current docs/mysql/02-isolation/anomaly-catalog.md:128 docs/mysql/02-isolation/anomaly-catalog.md### Error codes to retry on/paragraph@128 lesson-unit These are not the only possible statement or connection errors. Neither retry success nor a particular deadlock victim is guaranteed. Deadlock detection can be [disabled](https://dev.mysql.com/doc/refman/8.4/en/innodb-deadlock-detection.html), and this audit does not execute the timeout configuration alternatives. M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01249 current docs/mysql/02-isolation/anomaly-catalog.md:133 docs/mysql/02-isolation/anomaly-catalog.md### Further reading/line@133 lesson-unit ## Further reading M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01250 current docs/mysql/02-isolation/anomaly-catalog.md:135 docs/mysql/02-isolation/anomaly-catalog.md### Further reading/paragraph@135 lesson-unit - [Hermitage](https://github.com/ept/hermitage): separate runnable isolation tests - [Anomalies by engine](/concepts/anomalies-by-engine) - [The same catalog for PostgreSQL](/postgres/02-isolation/anomaly-catalog) M4 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01251 current docs/mysql/02-isolation/lost-update.md:1 docs/mysql/02-isolation/lost-update.md## Lost updates/line@1 lesson-unit # Lost updates M5 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01252 current docs/mysql/02-isolation/lost-update.md:3 docs/mysql/02-isolation/lost-update.md## Lost updates/paragraph@3 lesson-unit Two clients can read the same value, compute a replacement, and overwrite one another. The following InnoDB schedules run on MySQL 8.4.11 with reads **inside the updating transactions**. Each reads 100 and writes that saved value plus 10. Both commit without error, but the final balance is 110 rather than 120. M5 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01253 current docs/mysql/02-isolation/lost-update.md:8 docs/mysql/02-isolation/lost-update.md### At READ COMMITTED/line@8 lesson-unit ## At READ COMMITTED M5 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01254 current docs/mysql/02-isolation/lost-update.md:10 docs/mysql/02-isolation/lost-update.md### At READ COMMITTED/line@10 lesson-unit M5 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01255 current docs/mysql/02-isolation/lost-update.md:12 docs/mysql/02-isolation/lost-update.md### REPEATABLE READ does *not* save you/line@12 lesson-unit ## REPEATABLE READ does *not* save you M5 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01256 current docs/mysql/02-isolation/lost-update.md:14 docs/mysql/02-isolation/lost-update.md### REPEATABLE READ does *not* save you/paragraph@14 lesson-unit InnoDB UPDATE uses the current target row. It does not reject this stale literal replacement merely because B's earlier consistent read saw an older version. PostgreSQL's [REPEATABLE READ example](/postgres/02-isolation/lost-update) rejects that post-snapshot target change with 40001. Neither example establishes detection of every stale value read outside the updating transaction. M5 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01257 current docs/mysql/02-isolation/lost-update.md:20 docs/mysql/02-isolation/lost-update.md### REPEATABLE READ does *not* save you/line@20 lesson-unit ::: warning Protect the read-modify-write operation M5 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01258 current docs/mysql/02-isolation/lost-update.md:21 docs/mysql/02-isolation/lost-update.md### REPEATABLE READ does *not* save you/paragraph@21 lesson-unit Moving this unprotected schedule from READ COMMITTED to REPEATABLE READ does not repair it. An ORM operation that uses locks, a version check, or atomic arithmetic has different protection; not every ORM save has this race. M5 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01259 current docs/mysql/02-isolation/lost-update.md:24 docs/mysql/02-isolation/lost-update.md### REPEATABLE READ does *not* save you/line@24 lesson-unit ::: M5 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01260 current docs/mysql/02-isolation/lost-update.md:26 docs/mysql/02-isolation/lost-update.md### REPEATABLE READ does *not* save you/line@26 lesson-unit M5 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01261 current docs/mysql/02-isolation/lost-update.md:28 docs/mysql/02-isolation/lost-update.md### The fixes/line@28 lesson-unit ## The fixes M5 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01262 current docs/mysql/02-isolation/lost-update.md:30 docs/mysql/02-isolation/lost-update.md### The fixes/paragraph@30 lesson-unit The existing [fixing lost updates](/mysql/05-patterns/fixing-lost-updates) Scenarios execute atomic SQL arithmetic, a locking read before the decision, and a checked version-column UPDATE. Their assumptions and conflict responses belong to those examples. Atomic arithmetic fits increments; it is not a general repair for every replacement or business rule. All participating writers must respect the chosen protection, and an unmet version check needs explicit conflict handling. M5 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01263 current docs/mysql/02-isolation/lost-update.md:37 docs/mysql/02-isolation/lost-update.md### The fixes/paragraph@37 lesson-unit SERIALIZABLE explicit transactions also change this race by locking the reads, with possible deadlocks or waits. That is a Documented contract and an inference from the [locking-read rules](https://dev.mysql.com/doc/refman/8.4/en/innodb-locking-reads.html) and [SERIALIZABLE contract](https://dev.mysql.com/doc/refman/8.4/en/innodb-transaction-isolation-levels.html#isolevel_serializable), not a SERIALIZABLE execution of these two lost-update Scenarios. A standalone autocommit SELECT followed by a separate UPDATE does not retain that read lock. M5 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01264 current docs/mysql/02-isolation/lost-update.md:44 docs/mysql/02-isolation/lost-update.md### Further reading/line@44 lesson-unit ## Further reading M5 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01265 current docs/mysql/02-isolation/lost-update.md:46 docs/mysql/02-isolation/lost-update.md### Further reading/paragraph@46 lesson-unit - [Concepts: lost updates](/concepts/lost-update) - [The same lesson on PostgreSQL](/postgres/02-isolation/lost-update) M5 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01266 current docs/mysql/02-isolation/read-committed.md:1 docs/mysql/02-isolation/read-committed.md## Read Committed/line@1 lesson-unit # Read Committed M6 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01267 current docs/mysql/02-isolation/read-committed.md:3 docs/mysql/02-isolation/read-committed.md## Read Committed/paragraph@3 lesson-unit The [MySQL 8.4 READ COMMITTED contract](https://dev.mysql.com/doc/refman/8.4/en/innodb-transaction-isolation-levels.html#isolevel_read-committed) gives each **consistent nonlocking SELECT** a fresh snapshot of committed data, plus the transaction's own earlier changes. This is not the rule for every statement: UPDATE and locking reads can wait and use current rows. The following schedules run on MySQL 8.4.11, InnoDB, with explicitly selected levels. M6 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01268 current docs/mysql/02-isolation/read-committed.md:9 docs/mysql/02-isolation/read-committed.md### Non-repeatable reads/line@9 lesson-unit ## Non-repeatable reads M6 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01269 current docs/mysql/02-isolation/read-committed.md:11 docs/mysql/02-isolation/read-committed.md### Non-repeatable reads/paragraph@11 lesson-unit A reads 100, B commits 200, and A's next SELECT reads 200. The second part asserts a competing UPDATE's row-lock wait and eventual committed value 400. The plain SELECTs here do not wait for row writers; that does not exclude metadata-lock waits. M6 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01270 current docs/mysql/02-isolation/read-committed.md:15 docs/mysql/02-isolation/read-committed.md### Non-repeatable reads/line@15 lesson-unit M6 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01271 current docs/mysql/02-isolation/read-committed.md:17 docs/mysql/02-isolation/read-committed.md### Phantoms/line@17 lesson-unit ## Phantoms M6 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01272 current docs/mysql/02-isolation/read-committed.md:19 docs/mysql/02-isolation/read-committed.md### Phantoms/paragraph@19 lesson-unit B's committed INSERT changes A's matching set from two rows to three, total 1500. The count and total are returned SQL values, not a published application report. M6 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01273 current docs/mysql/02-isolation/read-committed.md:22 docs/mysql/02-isolation/read-committed.md### Phantoms/line@22 lesson-unit M6 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01274 current docs/mysql/02-isolation/read-committed.md:24 docs/mysql/02-isolation/read-committed.md### Read skew: a total that never existed/line@24 lesson-unit ## Read skew: a total that never existed M6 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01275 current docs/mysql/02-isolation/read-committed.md:26 docs/mysql/02-isolation/read-committed.md### Read skew: a total that never existed/paragraph@26 lesson-unit A reads alice before B's transfer and bob after it: the returned values add to 125 although each committed state totals 100. The repeated REPEATABLE READ schedule returns 25 and 75, using one snapshot with no writes by the reader. M6 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01276 current docs/mysql/02-isolation/read-committed.md:30 docs/mysql/02-isolation/read-committed.md### Read skew: a total that never existed/line@30 lesson-unit M6 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01277 current docs/mysql/02-isolation/read-committed.md:32 docs/mysql/02-isolation/read-committed.md### After the wait, the re-check/line@32 lesson-unit ## After the wait, the re-check M6 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01278 current docs/mysql/02-isolation/read-committed.md:34 docs/mysql/02-isolation/read-committed.md### After the wait, the re-check/paragraph@34 lesson-unit The manual's READ COMMITTED section documents semi-consistent UPDATE reads: a committed version can be used to check whether a locked row matches, followed by a current re-read and lock if it qualifies. Here B waits for A, then skips the row after A commits value 20. Zero affected rows and final values 20/30 are asserted. M6 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01279 current docs/mysql/02-isolation/read-committed.md:39 docs/mysql/02-isolation/read-committed.md### After the wait, the re-check/line@39 lesson-unit M6 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01280 current docs/mysql/02-isolation/read-committed.md:41 docs/mysql/02-isolation/read-committed.md### After the wait, the re-check/paragraph@41 lesson-unit Check affected rows instead of assuming a prior SELECT fixed the UPDATE's targets. For reports made from several nonlocking SELECTs, a REPEATABLE READ snapshot can exclude intervening concurrent commits, provided the reader does not itself change the data or mix current reads into that report. The manual also documents that READ COMMITTED disables gap locking for searches/index scans except foreign-key and duplicate-key checks. These schedules do not measure throughput or lock cost. M6 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01281 current docs/mysql/02-isolation/read-committed.md:48 docs/mysql/02-isolation/read-committed.md### Further reading/line@48 lesson-unit ## Further reading M6 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01282 current docs/mysql/02-isolation/read-committed.md:50 docs/mysql/02-isolation/read-committed.md### Further reading/paragraph@50 lesson-unit - [MySQL 8.4: Consistent Nonlocking Reads](https://dev.mysql.com/doc/refman/8.4/en/innodb-consistent-read.html) - [The same lesson on PostgreSQL](/postgres/02-isolation/read-committed) M6 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01283 current docs/mysql/02-isolation/repeatable-read.md:1 docs/mysql/02-isolation/repeatable-read.md## Repeatable Read/line@1 lesson-unit # Repeatable Read M7 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01284 current docs/mysql/02-isolation/repeatable-read.md:3 docs/mysql/02-isolation/repeatable-read.md## Repeatable Read/paragraph@3 lesson-unit The [MySQL 8.4 REPEATABLE READ contract](https://dev.mysql.com/doc/refman/8.4/en/innodb-transaction-isolation-levels.html#isolevel_repeatable-read) establishes the snapshot at the first **consistent table read**, not necessarily BEGIN or the first query of any kind. Later consistent SELECTs exclude concurrent commits after that point. The transaction's own earlier changes remain visible. START TRANSACTION WITH CONSISTENT SNAPSHOT is a separate documented way to take the snapshot at transaction start at this level; it is not executed below. M7 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01285 current docs/mysql/02-isolation/repeatable-read.md:10 docs/mysql/02-isolation/repeatable-read.md## Repeatable Read/paragraph@10 lesson-unit UPDATE, DELETE and locking reads such as SELECT FOR UPDATE/SHARE use current rows rather than that snapshot. They can wait for conflicting locks, and see the transaction's own writes. These rules concern InnoDB on MySQL 8.4; the displayed schedules run on 8.4.11. They do not promise that a write always succeeds. M7 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01286 current docs/mysql/02-isolation/repeatable-read.md:15 docs/mysql/02-isolation/repeatable-read.md### One snapshot, no phantoms/line@15 lesson-unit ## One snapshot, no phantoms M7 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01287 current docs/mysql/02-isolation/repeatable-read.md:17 docs/mysql/02-isolation/repeatable-read.md### One snapshot, no phantoms/paragraph@17 lesson-unit B commits 120 after A's BEGIN but before its first consistent SELECT. A includes 120 in its snapshot, excludes B's later 999 and new carol row, and includes its own change to bob (60). After COMMIT, a new standalone SELECT sees 999, 60, and carol. M7 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01288 current docs/mysql/02-isolation/repeatable-read.md:21 docs/mysql/02-isolation/repeatable-read.md### One snapshot, no phantoms/line@21 lesson-unit M7 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01289 current docs/mysql/02-isolation/repeatable-read.md:23 docs/mysql/02-isolation/repeatable-read.md### Current reads punch holes in the snapshot/line@23 lesson-unit ## Current reads punch holes in the snapshot M7 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01290 current docs/mysql/02-isolation/repeatable-read.md:25 docs/mysql/02-isolation/repeatable-read.md### Current reads punch holes in the snapshot/paragraph@25 lesson-unit A's snapshot reads 100. Its UPDATE uses B's committed 150 to produce 200, which A's later SELECT sees as its own write. In the second schedule it waits for B's uncommitted 300 and then produces 350 after B commits. M7 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01291 current docs/mysql/02-isolation/repeatable-read.md:29 docs/mysql/02-isolation/repeatable-read.md### Current reads punch holes in the snapshot/line@29 lesson-unit M7 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01292 current docs/mysql/02-isolation/repeatable-read.md:31 docs/mysql/02-isolation/repeatable-read.md### Current reads punch holes in the snapshot/line@31 lesson-unit ::: warning Porting from PostgreSQL? M7 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01293 current docs/mysql/02-isolation/repeatable-read.md:32 docs/mysql/02-isolation/repeatable-read.md### Current reads punch holes in the snapshot/paragraph@32 lesson-unit For these post-snapshot target-row changes, PostgreSQL REPEATABLE READ rejects the UPDATE with 40001; see its [executed conflict cases](/postgres/02-isolation/repeatable-read). InnoDB accepts these current-row UPDATEs. It does not reject them merely because the earlier snapshot was stale. It can still fail with a deadlock (1213, SQLSTATE 40001), timeout, or constraint error. Do not infer that 40001 never occurs on MySQL. M7 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01294 current docs/mysql/02-isolation/repeatable-read.md:37 docs/mysql/02-isolation/repeatable-read.md### Current reads punch holes in the snapshot/line@37 lesson-unit ::: M7 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01295 current docs/mysql/02-isolation/repeatable-read.md:39 docs/mysql/02-isolation/repeatable-read.md### Your DELETE and your SELECT live in different worlds/line@39 lesson-unit ## Your DELETE and your SELECT live in different worlds M7 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01296 current docs/mysql/02-isolation/repeatable-read.md:41 docs/mysql/02-isolation/repeatable-read.md### Your DELETE and your SELECT live in different worlds/paragraph@41 lesson-unit A's DELETE finds no current row with balance 20, yet its consistent SELECT still sees bob with snapshot balance 20. The Scenario asserts zero deleted rows and the retained snapshot value; this is not a new-row phantom demonstration. M7 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01297 current docs/mysql/02-isolation/repeatable-read.md:45 docs/mysql/02-isolation/repeatable-read.md### Your DELETE and your SELECT live in different worlds/line@45 lesson-unit M7 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01298 current docs/mysql/02-isolation/repeatable-read.md:47 docs/mysql/02-isolation/repeatable-read.md### Your DELETE and your SELECT live in different worlds/paragraph@47 lesson-unit The [consistent-read manual](https://dev.mysql.com/doc/refman/8.4/en/innodb-consistent-read.html) documents own-write/current-DML exceptions. A stable snapshot is not a guarantee that every operation sees the same rows, or that a multi-row business rule survives concurrent writers. See [lost updates](/mysql/02-isolation/lost-update) and [write skew](/mysql/02-isolation/serializable). A repair must protect the reads and decisions before writing, with participation by all relevant writers. M7 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01299 current docs/mysql/02-isolation/repeatable-read.md:54 docs/mysql/02-isolation/repeatable-read.md### Further reading/line@54 lesson-unit ## Further reading M7 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01300 current docs/mysql/02-isolation/repeatable-read.md:56 docs/mysql/02-isolation/repeatable-read.md### Further reading/paragraph@56 lesson-unit - [MySQL 8.4: Locking Reads](https://dev.mysql.com/doc/refman/8.4/en/innodb-locking-reads.html) - [MySQL 8.4: START TRANSACTION](https://dev.mysql.com/doc/refman/8.4/en/commit.html) - [The same lesson on PostgreSQL](/postgres/02-isolation/repeatable-read) M7 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01301 current docs/mysql/02-isolation/serializable.md:1 docs/mysql/02-isolation/serializable.md## Serializable/line@1 lesson-unit # Serializable M8 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01302 current docs/mysql/02-isolation/serializable.md:3 docs/mysql/02-isolation/serializable.md## Serializable/paragraph@3 lesson-unit A cross-row business rule can fail even when concurrent transactions write different rows. These MySQL 8.4.11 InnoDB Scenarios use the rule that at least one doctor stays on call. Each request counts two doctors and removes a different one. Each request would preserve the rule if it ran alone from that state. M8 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01303 current docs/mysql/02-isolation/serializable.md:8 docs/mysql/02-isolation/serializable.md### Write skew at REPEATABLE READ/line@8 lesson-unit ## Write skew at REPEATABLE READ M8 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01304 current docs/mysql/02-isolation/serializable.md:10 docs/mysql/02-isolation/serializable.md### Write skew at REPEATABLE READ/paragraph@10 lesson-unit Both requests commit in the displayed snapshot-read schedule. The final count is zero. This demonstrates item write skew (G2-item), not every predicate anomaly. M8 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01305 current docs/mysql/02-isolation/serializable.md:13 docs/mysql/02-isolation/serializable.md### Write skew at REPEATABLE READ/line@13 lesson-unit M8 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01306 current docs/mysql/02-isolation/serializable.md:15 docs/mysql/02-isolation/serializable.md### SERIALIZABLE stops it (with locks)/line@15 lesson-unit ## SERIALIZABLE stops it (with locks) M8 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01307 current docs/mysql/02-isolation/serializable.md:17 docs/mysql/02-isolation/serializable.md### SERIALIZABLE stops it (with locks)/paragraph@17 lesson-unit The [MySQL 8.4 SERIALIZABLE contract](https://dev.mysql.com/doc/refman/8.4/en/innodb-transaction-isolation-levels.html#isolevel_serializable) uses shared locking reads for plain SELECTs in explicit multi-statement transactions, as executed here, or when autocommit is disabled. Lock coverage depends on the query and index, including relevant ranges, not just returned rows. A's UPDATE waits for B; B's UPDATE closes the cycle. With deadlock detection enabled, this schedule selects B as victim (1213), A commits, and one doctor remains. The victim and detection timing are not universal guarantees. M8 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01308 current docs/mysql/02-isolation/serializable.md:25 docs/mysql/02-isolation/serializable.md### SERIALIZABLE stops it (with locks)/line@25 lesson-unit M8 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01309 current docs/mysql/02-isolation/serializable.md:27 docs/mysql/02-isolation/serializable.md### SERIALIZABLE stops it (with locks)/paragraph@27 lesson-unit The fresh B attempt repeats the count and declines to leave. Retry the whole transaction with fresh reads and decisions, or return a controlled failure. A successful retry is not guaranteed. The [error-handling contract](https://dev.mysql.com/doc/refman/8.4/en/innodb-error-handling.html) says deadlocks roll back the entire transaction. With [deadlock detection disabled](https://dev.mysql.com/doc/refman/8.4/en/innodb-deadlock-detection.html), lock-wait timeouts can resolve the cycle instead; their rollback scope depends on `innodb_rollback_on_timeout`. These configuration alternatives are not executed here. M8 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01310 current docs/mysql/02-isolation/serializable.md:36 docs/mysql/02-isolation/serializable.md### SERIALIZABLE stops it (with locks)/line@36 lesson-unit ::: info Two databases, different conflict handling M8 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01311 current docs/mysql/02-isolation/serializable.md:37 docs/mysql/02-isolation/serializable.md### SERIALIZABLE stops it (with locks)/paragraph@37 lesson-unit PostgreSQL's [SSI example](/postgres/02-isolation/serializable) detects this dependency conflict without the count SELECTs taking InnoDB-style row locks. PostgreSQL SERIALIZABLE can still wait for ordinary conflicting writes or locks, and 40001 is not confined to COMMIT. InnoDB deadlocks are not confined to SERIALIZABLE. M8 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01312 current docs/mysql/02-isolation/serializable.md:41 docs/mysql/02-isolation/serializable.md### SERIALIZABLE stops it (with locks)/line@41 lesson-unit ::: M8 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01313 current docs/mysql/02-isolation/serializable.md:43 docs/mysql/02-isolation/serializable.md### SERIALIZABLE stops it (with locks)/line@43 lesson-unit ::: warning Not every SERIALIZABLE SELECT locks M8 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01314 current docs/mysql/02-isolation/serializable.md:44 docs/mysql/02-isolation/serializable.md### SERIALIZABLE stops it (with locks)/paragraph@44 lesson-unit A standalone autocommit SELECT can be a nonlocking consistent read. The final part of this Scenario asserts that it reads the last committed on-call count during B's uncommitted change. With autocommit disabled, the same SELECT waits until B rolls back. Applying a session level does not combine separate autocommit statements into one protected read-modify-write transaction. M8 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01315 current docs/mysql/02-isolation/serializable.md:49 docs/mysql/02-isolation/serializable.md### SERIALIZABLE stops it (with locks)/line@49 lesson-unit ::: M8 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01316 current docs/mysql/02-isolation/serializable.md:51 docs/mysql/02-isolation/serializable.md### SERIALIZABLE stops it (with locks)/paragraph@51 lesson-unit **Entailed guarantee:** for this rule, if every relevant request uses the SERIALIZABLE transaction boundary and checks the count before removing a doctor, the locking read prevents a competing removal from silently invalidating that decision before commit. A serial execution of the requests preserves at least one doctor; waits or aborted attempts must be handled without reporting a commit. This derivation uses the manual's locking-read and SERIALIZABLE contracts, not just the observed count of one. Other writers that bypass the check can still break the rule. Suitable explicit coordination can also protect it; SERIALIZABLE is not the only possible repair, and no cost comparison is measured here. M8 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Entailed where marked, derivation and contracts in the named section; D/M separately identified Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01317 current docs/mysql/02-isolation/serializable.md:61 docs/mysql/02-isolation/serializable.md### Further reading/line@61 lesson-unit ## Further reading M8 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01318 current docs/mysql/02-isolation/serializable.md:63 docs/mysql/02-isolation/serializable.md### Further reading/paragraph@63 lesson-unit - [MySQL 8.4: Locks Set by Different SQL Statements](https://dev.mysql.com/doc/refman/8.4/en/innodb-locks-set.html) - [MySQL 8.4: Deadlock Detection](https://dev.mysql.com/doc/refman/8.4/en/innodb-deadlock-detection.html) - [The same lesson on PostgreSQL](/postgres/02-isolation/serializable) M8 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01319 current docs/mysql/02-isolation/snapshots-and-the-four-levels.md:1 docs/mysql/02-isolation/snapshots-and-the-four-levels.md## Snapshots & the four levels/line@1 lesson-unit # Snapshots & the four levels M9 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01320 current docs/mysql/02-isolation/snapshots-and-the-four-levels.md:3 docs/mysql/02-isolation/snapshots-and-the-four-levels.md## Snapshots & the four levels/paragraph@3 lesson-unit The [MySQL 8.4 isolation manual](https://dev.mysql.com/doc/refman/8.4/en/innodb-transaction-isolation-levels.html) documents four InnoDB levels, with REPEATABLE READ as the server default. These lessons execute Scenarios on **MySQL 8.4.11 with InnoDB tables**. An application or driver can override the default; inspect its connection settings. M9 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01321 current docs/mysql/02-isolation/snapshots-and-the-four-levels.md:8 docs/mysql/02-isolation/snapshots-and-the-four-levels.md## Snapshots & the four levels/paragraph@8 lesson-unit A consistent nonlocking SELECT uses MVCC to read older committed versions instead of waiting for a concurrent row writer. This is not a promise that SELECT never waits: [metadata locks](https://dev.mysql.com/doc/refman/8.4/en/metadata-locking.html) can conflict with DDL, and locking SELECTs have different behavior. M9 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01322 current docs/mysql/02-isolation/snapshots-and-the-four-levels.md:13 docs/mysql/02-isolation/snapshots-and-the-four-levels.md## Snapshots & the four levels/paragraph@13 lesson-unit The following table gives **Documented contracts**, not all-level executions. It concerns concurrent changes to InnoDB tables; own writes remain visible. M9 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01323 current docs/mysql/02-isolation/snapshots-and-the-four-levels.md:16 docs/mysql/02-isolation/snapshots-and-the-four-levels.md## Snapshots & the four levels/table.row@16.cell[0] catalog-cell Level M9 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01324 current docs/mysql/02-isolation/snapshots-and-the-four-levels.md:16 docs/mysql/02-isolation/snapshots-and-the-four-levels.md## Snapshots & the four levels/table.row@16.cell[1] catalog-cell Plain table SELECT visibility M9 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02345 current docs/mysql/02-isolation/snapshots-and-the-four-levels.md:16 docs/mysql/02-isolation/snapshots-and-the-four-levels.md## Snapshots & the four levels/table.row@16.cell[2] catalog-cell Important boundary M9 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01325 current docs/mysql/02-isolation/snapshots-and-the-four-levels.md:17 docs/mysql/02-isolation/snapshots-and-the-four-levels.md## Snapshots & the four levels/table.row@17.cell[0] catalog-cell --- M9 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01326 current docs/mysql/02-isolation/snapshots-and-the-four-levels.md:17 docs/mysql/02-isolation/snapshots-and-the-four-levels.md## Snapshots & the four levels/table.row@17.cell[1] catalog-cell --- M9 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02346 current docs/mysql/02-isolation/snapshots-and-the-four-levels.md:17 docs/mysql/02-isolation/snapshots-and-the-four-levels.md## Snapshots & the four levels/table.row@17.cell[2] catalog-cell --- M9 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01327 current docs/mysql/02-isolation/snapshots-and-the-four-levels.md:18 docs/mysql/02-isolation/snapshots-and-the-four-levels.md## Snapshots & the four levels/table.row@18.cell[0] catalog-cell READ UNCOMMITTED M9 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01328 current docs/mysql/02-isolation/snapshots-and-the-four-levels.md:18 docs/mysql/02-isolation/snapshots-and-the-four-levels.md## Snapshots & the four levels/table.row@18.cell[1] catalog-cell May expose uncommitted versions; no consistent snapshot promise M9 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02347 current docs/mysql/02-isolation/snapshots-and-the-four-levels.md:18 docs/mysql/02-isolation/snapshots-and-the-four-levels.md## Snapshots & the four levels/table.row@18.cell[2] catalog-cell A dirty value may be rolled back M9 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01329 current docs/mysql/02-isolation/snapshots-and-the-four-levels.md:19 docs/mysql/02-isolation/snapshots-and-the-four-levels.md## Snapshots & the four levels/table.row@19.cell[0] catalog-cell READ COMMITTED M9 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01330 current docs/mysql/02-isolation/snapshots-and-the-four-levels.md:19 docs/mysql/02-isolation/snapshots-and-the-four-levels.md## Snapshots & the four levels/table.row@19.cell[1] catalog-cell Fresh snapshot per consistent read M9 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02348 current docs/mysql/02-isolation/snapshots-and-the-four-levels.md:19 docs/mysql/02-isolation/snapshots-and-the-four-levels.md## Snapshots & the four levels/table.row@19.cell[2] catalog-cell Separate SELECTs can disagree after a concurrent commit M9 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01331 current docs/mysql/02-isolation/snapshots-and-the-four-levels.md:20 docs/mysql/02-isolation/snapshots-and-the-four-levels.md## Snapshots & the four levels/table.row@20.cell[0] catalog-cell REPEATABLE READ, default M9 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01332 current docs/mysql/02-isolation/snapshots-and-the-four-levels.md:20 docs/mysql/02-isolation/snapshots-and-the-four-levels.md## Snapshots & the four levels/table.row@20.cell[1] catalog-cell Snapshot established by the first consistent read M9 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02349 current docs/mysql/02-isolation/snapshots-and-the-four-levels.md:20 docs/mysql/02-isolation/snapshots-and-the-four-levels.md## Snapshots & the four levels/table.row@20.cell[2] catalog-cell Own writes are visible; UPDATE, DELETE and locking reads use current rows M9 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01333 current docs/mysql/02-isolation/snapshots-and-the-four-levels.md:21 docs/mysql/02-isolation/snapshots-and-the-four-levels.md## Snapshots & the four levels/table.row@21.cell[0] catalog-cell SERIALIZABLE M9 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01334 current docs/mysql/02-isolation/snapshots-and-the-four-levels.md:21 docs/mysql/02-isolation/snapshots-and-the-four-levels.md## Snapshots & the four levels/table.row@21.cell[1] catalog-cell Plain SELECTs lock in explicit transactions or with autocommit disabled M9 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02350 current docs/mysql/02-isolation/snapshots-and-the-four-levels.md:21 docs/mysql/02-isolation/snapshots-and-the-four-levels.md## Snapshots & the four levels/table.row@21.cell[2] catalog-cell A standalone autocommit SELECT can use a nonlocking consistent read M9 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01335 current docs/mysql/02-isolation/snapshots-and-the-four-levels.md:23 docs/mysql/02-isolation/snapshots-and-the-four-levels.md## Snapshots & the four levels/paragraph@23 lesson-unit See [consistent reads](https://dev.mysql.com/doc/refman/8.4/en/innodb-consistent-read.html) for own-write visibility and DML exceptions, and [SERIALIZABLE](/mysql/02-isolation/serializable) for the executed autocommit distinction. Do not mix the snapshot rule with a claim about every statement or every SQL function. M9 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01336 current docs/mysql/02-isolation/snapshots-and-the-four-levels.md:28 docs/mysql/02-isolation/snapshots-and-the-four-levels.md## Snapshots & the four levels/paragraph@28 lesson-unit The [SET TRANSACTION contract](https://dev.mysql.com/doc/refman/8.4/en/set-transaction.html) distinguishes a setting for the next transaction (`SET TRANSACTION`) from subsequent session transactions (`SET SESSION TRANSACTION`). Set the next-transaction level before starting it. MySQL does not use PostgreSQL's BEGIN ISOLATION LEVEL syntax. M9 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01337 current docs/mysql/02-isolation/snapshots-and-the-four-levels.md:33 docs/mysql/02-isolation/snapshots-and-the-four-levels.md### READ UNCOMMITTED means it/line@33 lesson-unit ## READ UNCOMMITTED means it M9 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01338 current docs/mysql/02-isolation/snapshots-and-the-four-levels.md:35 docs/mysql/02-isolation/snapshots-and-the-four-levels.md### READ UNCOMMITTED means it/paragraph@35 lesson-unit In this schedule B reads A's uncommitted 999, then reads 100 after A rolls back. The 999 existed as uncommitted data, but never entered committed history. No external application action is executed by this SELECT-result model. M9 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01339 current docs/mysql/02-isolation/snapshots-and-the-four-levels.md:39 docs/mysql/02-isolation/snapshots-and-the-four-levels.md### READ UNCOMMITTED means it/line@39 lesson-unit M9 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01340 current docs/mysql/02-isolation/snapshots-and-the-four-levels.md:41 docs/mysql/02-isolation/snapshots-and-the-four-levels.md### READ UNCOMMITTED means it/paragraph@41 lesson-unit READ UNCOMMITTED permits dirty reads; it does not require every read to be dirty. PostgreSQL instead maps that level to READ COMMITTED, as documented in its [version 18 isolation manual](https://www.postgresql.org/docs/18/transaction-iso.html). Continue with [READ COMMITTED](/mysql/02-isolation/read-committed), [REPEATABLE READ](/mysql/02-isolation/repeatable-read), [SERIALIZABLE](/mysql/02-isolation/serializable), and [lost updates](/mysql/02-isolation/lost-update). M9 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01341 current docs/mysql/02-isolation/snapshots-and-the-four-levels.md:49 docs/mysql/02-isolation/snapshots-and-the-four-levels.md### Further reading/line@49 lesson-unit ## Further reading M9 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01342 current docs/mysql/02-isolation/snapshots-and-the-four-levels.md:51 docs/mysql/02-isolation/snapshots-and-the-four-levels.md### Further reading/paragraph@51 lesson-unit - [MySQL 8.4: Transaction Isolation Levels](https://dev.mysql.com/doc/refman/8.4/en/innodb-transaction-isolation-levels.html) - [The same lesson on PostgreSQL](/postgres/02-isolation/snapshots-and-the-four-levels) M9 MySQL 8.4 manual contracts; MySQL 8.4.11 linked executions; InnoDB, operations and conditions in this paragraph/cell and registry Documented contracts and/or linked Demonstrated schedule as identified in paragraph or cell; headings/navigation are editorial Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01343 current scenarios/mysql/01-basics/aborted-transaction.yaml:1 scenarios/mysql/01-basics/aborted-transaction.yaml#title title A duplicate-key error leaves the InnoDB transaction open M10 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01344 current scenarios/mysql/01-basics/aborted-transaction.yaml:2 scenarios/mysql/01-basics/aborted-transaction.yaml#claim claim The demonstrated duplicate-key INSERT error (1062, without IGNORE) rolls back that statement; the earlier and later INSERTs commit in the same InnoDB transaction. This does not describe deadlock or connection errors. M10 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01345 current scenarios/mysql/01-basics/aborted-transaction.yaml:6 scenarios/mysql/01-basics/aborted-transaction.yaml#setup setup "CREATE TABLE items (id int PRIMARY KEY, name varchar(50) NOT NULL UNIQUE) ENGINE=InnoDB; INSERT INTO items VALUES (1, 'widget'); " M10 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01346 current scenarios/mysql/01-basics/aborted-transaction.yaml:9 scenarios/mysql/01-basics/aborted-transaction.yaml#sessions[0] sessions[0] A M10 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01347 current scenarios/mysql/01-basics/aborted-transaction.yaml:11 scenarios/mysql/01-basics/aborted-transaction.yaml#steps[0].A A BEGIN M10 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01348 current scenarios/mysql/01-basics/aborted-transaction.yaml:12 scenarios/mysql/01-basics/aborted-transaction.yaml#steps[1].A A INSERT INTO items VALUES (2, 'gadget') M10 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01349 current scenarios/mysql/01-basics/aborted-transaction.yaml:14 scenarios/mysql/01-basics/aborted-transaction.yaml#steps[2].A.fails fails INSERT INTO items VALUES (3, 'widget') M10 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01350 current scenarios/mysql/01-basics/aborted-transaction.yaml:15 scenarios/mysql/01-basics/aborted-transaction.yaml#steps[2].error error 1062 M10 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01351 current scenarios/mysql/01-basics/aborted-transaction.yaml:16 scenarios/mysql/01-basics/aborted-transaction.yaml#steps[2].comment comment ER_DUP_ENTRY M10 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01352 current scenarios/mysql/01-basics/aborted-transaction.yaml:18 scenarios/mysql/01-basics/aborted-transaction.yaml#steps[3].note note This 1062 error leaves the earlier INSERT intact. A chooses to continue and COMMIT. M10 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01353 current scenarios/mysql/01-basics/aborted-transaction.yaml:19 scenarios/mysql/01-basics/aborted-transaction.yaml#steps[4].A A INSERT INTO items VALUES (3, 'doohickey') M10 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01354 current scenarios/mysql/01-basics/aborted-transaction.yaml:20 scenarios/mysql/01-basics/aborted-transaction.yaml#steps[5].A A COMMIT M10 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01355 current scenarios/mysql/01-basics/aborted-transaction.yaml:22 scenarios/mysql/01-basics/aborted-transaction.yaml#steps[6].A A SELECT id, name FROM items ORDER BY id M10 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01356 current scenarios/mysql/01-basics/aborted-transaction.yaml:24 scenarios/mysql/01-basics/aborted-transaction.yaml#steps[6].expect[0].id id 1 M10 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01357 current scenarios/mysql/01-basics/aborted-transaction.yaml:24 scenarios/mysql/01-basics/aborted-transaction.yaml#steps[6].expect[0].name name widget M10 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01358 current scenarios/mysql/01-basics/aborted-transaction.yaml:25 scenarios/mysql/01-basics/aborted-transaction.yaml#steps[6].expect[1].id id 2 M10 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01359 current scenarios/mysql/01-basics/aborted-transaction.yaml:25 scenarios/mysql/01-basics/aborted-transaction.yaml#steps[6].expect[1].name name gadget M10 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01360 current scenarios/mysql/01-basics/aborted-transaction.yaml:26 scenarios/mysql/01-basics/aborted-transaction.yaml#steps[6].expect[2].id id 3 M10 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01361 current scenarios/mysql/01-basics/aborted-transaction.yaml:26 scenarios/mysql/01-basics/aborted-transaction.yaml#steps[6].expect[2].name name doohickey M10 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01362 current scenarios/mysql/01-basics/aborted-transaction.yaml:27 scenarios/mysql/01-basics/aborted-transaction.yaml#steps[6].comment comment survived the error in the middle M10 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01363 current scenarios/mysql/01-basics/atomicity.yaml:1 scenarios/mysql/01-basics/atomicity.yaml#title title Atomicity: all or nothing M11 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01364 current scenarios/mysql/01-basics/atomicity.yaml:2 scenarios/mysql/01-basics/atomicity.yaml#claim claim On InnoDB, the demonstrated CHECK error leaves bob's earlier credit in A's transaction; explicit ROLLBACK then discards both balances' changes. M11 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01365 current scenarios/mysql/01-basics/atomicity.yaml:5 scenarios/mysql/01-basics/atomicity.yaml#setup setup "CREATE TABLE accounts ( id int PRIMARY KEY, owner varchar(20) NOT NULL, balance int NOT NULL CHECK (balance >= 0) ) ENGINE=InnoDB; INSERT INTO accounts VALUES (1, 'alice', 100), (2, 'bob', 50); " M11 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01366 current scenarios/mysql/01-basics/atomicity.yaml:12 scenarios/mysql/01-basics/atomicity.yaml#sessions[0] sessions[0] A M11 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01367 current scenarios/mysql/01-basics/atomicity.yaml:12 scenarios/mysql/01-basics/atomicity.yaml#sessions[1] sessions[1] B M11 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01368 current scenarios/mysql/01-basics/atomicity.yaml:14 scenarios/mysql/01-basics/atomicity.yaml#steps[0].note note A transfers 150 from alice to bob. Crediting bob works fine… M11 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01369 current scenarios/mysql/01-basics/atomicity.yaml:15 scenarios/mysql/01-basics/atomicity.yaml#steps[1].A A BEGIN M11 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01370 current scenarios/mysql/01-basics/atomicity.yaml:16 scenarios/mysql/01-basics/atomicity.yaml#steps[2].A A UPDATE accounts SET balance = balance + 150 WHERE owner = 'bob' M11 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01371 current scenarios/mysql/01-basics/atomicity.yaml:17 scenarios/mysql/01-basics/atomicity.yaml#steps[2].tl tl credit bob +150 (uncommitted) M11 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01372 current scenarios/mysql/01-basics/atomicity.yaml:19 scenarios/mysql/01-basics/atomicity.yaml#steps[3].B B SELECT balance FROM accounts WHERE owner = 'bob' M11 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01373 current scenarios/mysql/01-basics/atomicity.yaml:20 scenarios/mysql/01-basics/atomicity.yaml#steps[3].expect[0].balance balance 50 M11 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01374 current scenarios/mysql/01-basics/atomicity.yaml:21 scenarios/mysql/01-basics/atomicity.yaml#steps[3].comment comment B can't see A's uncommitted credit M11 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01375 current scenarios/mysql/01-basics/atomicity.yaml:22 scenarios/mysql/01-basics/atomicity.yaml#steps[3].tl tl read bob → 50 (credit hidden) M11 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01376 current scenarios/mysql/01-basics/atomicity.yaml:24 scenarios/mysql/01-basics/atomicity.yaml#steps[4].note note …but debiting alice violates the CHECK constraint; she only has 100. M11 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01377 current scenarios/mysql/01-basics/atomicity.yaml:25 scenarios/mysql/01-basics/atomicity.yaml#steps[5].A.fails fails UPDATE accounts SET balance = balance - 150 WHERE owner = 'alice' M11 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01378 current scenarios/mysql/01-basics/atomicity.yaml:26 scenarios/mysql/01-basics/atomicity.yaml#steps[5].error error 3819 M11 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01379 current scenarios/mysql/01-basics/atomicity.yaml:27 scenarios/mysql/01-basics/atomicity.yaml#steps[5].comment comment ER_CHECK_CONSTRAINT_VIOLATED M11 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01380 current scenarios/mysql/01-basics/atomicity.yaml:28 scenarios/mysql/01-basics/atomicity.yaml#steps[5].tl tl debit alice −150 M11 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01381 current scenarios/mysql/01-basics/atomicity.yaml:30 scenarios/mysql/01-basics/atomicity.yaml#steps[6].note note A's SELECT still sees bob's successful credit. The explicit ROLLBACK below discards it. M11 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01382 current scenarios/mysql/01-basics/atomicity.yaml:31 scenarios/mysql/01-basics/atomicity.yaml#steps[7].A A SELECT owner, balance FROM accounts ORDER BY id M11 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01383 current scenarios/mysql/01-basics/atomicity.yaml:32 scenarios/mysql/01-basics/atomicity.yaml#steps[7].expect[0].owner owner alice M11 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01384 current scenarios/mysql/01-basics/atomicity.yaml:32 scenarios/mysql/01-basics/atomicity.yaml#steps[7].expect[0].balance balance 100 M11 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01385 current scenarios/mysql/01-basics/atomicity.yaml:32 scenarios/mysql/01-basics/atomicity.yaml#steps[7].expect[1].owner owner bob M11 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01386 current scenarios/mysql/01-basics/atomicity.yaml:32 scenarios/mysql/01-basics/atomicity.yaml#steps[7].expect[1].balance balance 200 M11 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01387 current scenarios/mysql/01-basics/atomicity.yaml:33 scenarios/mysql/01-basics/atomicity.yaml#steps[8].A A ROLLBACK M11 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01388 current scenarios/mysql/01-basics/atomicity.yaml:34 scenarios/mysql/01-basics/atomicity.yaml#steps[8].tl tl ROLLBACK; bob's credit gone too M11 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01389 current scenarios/mysql/01-basics/atomicity.yaml:36 scenarios/mysql/01-basics/atomicity.yaml#steps[9].B B SELECT owner, balance FROM accounts ORDER BY id M11 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01390 current scenarios/mysql/01-basics/atomicity.yaml:38 scenarios/mysql/01-basics/atomicity.yaml#steps[9].expect[0].owner owner alice M11 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01391 current scenarios/mysql/01-basics/atomicity.yaml:38 scenarios/mysql/01-basics/atomicity.yaml#steps[9].expect[0].balance balance 100 M11 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01392 current scenarios/mysql/01-basics/atomicity.yaml:39 scenarios/mysql/01-basics/atomicity.yaml#steps[9].expect[1].owner owner bob M11 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01393 current scenarios/mysql/01-basics/atomicity.yaml:39 scenarios/mysql/01-basics/atomicity.yaml#steps[9].expect[1].balance balance 50 M11 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01394 current scenarios/mysql/01-basics/atomicity.yaml:40 scenarios/mysql/01-basics/atomicity.yaml#steps[9].tl tl read → alice 100, bob 50 (untouched) M11 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01395 current scenarios/mysql/01-basics/autocommit-visibility.yaml:1 scenarios/mysql/01-basics/autocommit-visibility.yaml#title title Autocommit and visibility M12 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01396 current scenarios/mysql/01-basics/autocommit-visibility.yaml:2 scenarios/mysql/01-basics/autocommit-visibility.yaml#claim claim With autocommit=1 on InnoDB, A's successful standalone UPDATE is visible to B's later standalone SELECT. B excludes A's explicit-transaction UPDATE until COMMIT; a pre-existing REPEATABLE READ snapshot need not refresh. M12 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01397 current scenarios/mysql/01-basics/autocommit-visibility.yaml:6 scenarios/mysql/01-basics/autocommit-visibility.yaml#setup setup "CREATE TABLE accounts (id int PRIMARY KEY, owner varchar(20) NOT NULL, balance int NOT NULL) ENGINE=InnoDB; INSERT INTO accounts VALUES (1, 'alice', 100); " M12 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01398 current scenarios/mysql/01-basics/autocommit-visibility.yaml:9 scenarios/mysql/01-basics/autocommit-visibility.yaml#sessions[0] sessions[0] A M12 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01399 current scenarios/mysql/01-basics/autocommit-visibility.yaml:9 scenarios/mysql/01-basics/autocommit-visibility.yaml#sessions[1] sessions[1] B M12 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01400 current scenarios/mysql/01-basics/autocommit-visibility.yaml:11 scenarios/mysql/01-basics/autocommit-visibility.yaml#steps[0].A A SELECT @@autocommit AS autocommit, @@transaction_isolation AS isolation, @@default_storage_engine AS engine M12 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01401 current scenarios/mysql/01-basics/autocommit-visibility.yaml:12 scenarios/mysql/01-basics/autocommit-visibility.yaml#steps[0].expect[0].autocommit autocommit 1 M12 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01402 current scenarios/mysql/01-basics/autocommit-visibility.yaml:12 scenarios/mysql/01-basics/autocommit-visibility.yaml#steps[0].expect[0].isolation isolation REPEATABLE-READ M12 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01403 current scenarios/mysql/01-basics/autocommit-visibility.yaml:12 scenarios/mysql/01-basics/autocommit-visibility.yaml#steps[0].expect[0].engine engine InnoDB M12 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01404 current scenarios/mysql/01-basics/autocommit-visibility.yaml:13 scenarios/mysql/01-basics/autocommit-visibility.yaml#steps[1].B B SELECT @@autocommit AS autocommit M12 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01405 current scenarios/mysql/01-basics/autocommit-visibility.yaml:14 scenarios/mysql/01-basics/autocommit-visibility.yaml#steps[1].expect[0].autocommit autocommit 1 M12 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01406 current scenarios/mysql/01-basics/autocommit-visibility.yaml:15 scenarios/mysql/01-basics/autocommit-visibility.yaml#steps[2].note note No BEGIN; the UPDATE is its own transaction, committed the instant it finishes. M12 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01407 current scenarios/mysql/01-basics/autocommit-visibility.yaml:16 scenarios/mysql/01-basics/autocommit-visibility.yaml#steps[3].A A UPDATE accounts SET balance = 150 WHERE id = 1 M12 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01408 current scenarios/mysql/01-basics/autocommit-visibility.yaml:17 scenarios/mysql/01-basics/autocommit-visibility.yaml#steps[3].tl tl UPDATE balance = 150 (autocommit) M12 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01409 current scenarios/mysql/01-basics/autocommit-visibility.yaml:19 scenarios/mysql/01-basics/autocommit-visibility.yaml#steps[4].B B SELECT balance FROM accounts WHERE id = 1 M12 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01410 current scenarios/mysql/01-basics/autocommit-visibility.yaml:20 scenarios/mysql/01-basics/autocommit-visibility.yaml#steps[4].expect[0].balance balance 150 M12 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01411 current scenarios/mysql/01-basics/autocommit-visibility.yaml:21 scenarios/mysql/01-basics/autocommit-visibility.yaml#steps[4].comment comment B sees it immediately M12 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01412 current scenarios/mysql/01-basics/autocommit-visibility.yaml:22 scenarios/mysql/01-basics/autocommit-visibility.yaml#steps[4].tl tl SELECT balance → 150 (visible at once) M12 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01413 current scenarios/mysql/01-basics/autocommit-visibility.yaml:24 scenarios/mysql/01-basics/autocommit-visibility.yaml#steps[5].note note Inside an explicit transaction, A's change is invisible to B… M12 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01414 current scenarios/mysql/01-basics/autocommit-visibility.yaml:25 scenarios/mysql/01-basics/autocommit-visibility.yaml#steps[6].A A BEGIN M12 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01415 current scenarios/mysql/01-basics/autocommit-visibility.yaml:26 scenarios/mysql/01-basics/autocommit-visibility.yaml#steps[7].A A UPDATE accounts SET balance = 999 WHERE id = 1 M12 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01416 current scenarios/mysql/01-basics/autocommit-visibility.yaml:27 scenarios/mysql/01-basics/autocommit-visibility.yaml#steps[7].tl tl UPDATE balance = 999 (uncommitted) M12 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01417 current scenarios/mysql/01-basics/autocommit-visibility.yaml:29 scenarios/mysql/01-basics/autocommit-visibility.yaml#steps[8].B B SELECT balance FROM accounts WHERE id = 1 M12 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01418 current scenarios/mysql/01-basics/autocommit-visibility.yaml:30 scenarios/mysql/01-basics/autocommit-visibility.yaml#steps[8].expect[0].balance balance 150 M12 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01419 current scenarios/mysql/01-basics/autocommit-visibility.yaml:31 scenarios/mysql/01-basics/autocommit-visibility.yaml#steps[8].comment comment still the old value M12 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01420 current scenarios/mysql/01-basics/autocommit-visibility.yaml:32 scenarios/mysql/01-basics/autocommit-visibility.yaml#steps[8].tl tl SELECT balance → 150 (A's change hidden) M12 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01421 current scenarios/mysql/01-basics/autocommit-visibility.yaml:34 scenarios/mysql/01-basics/autocommit-visibility.yaml#steps[9].note note B's next standalone SELECT takes a new snapshot after A commits. M12 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01422 current scenarios/mysql/01-basics/autocommit-visibility.yaml:35 scenarios/mysql/01-basics/autocommit-visibility.yaml#steps[10].A A COMMIT M12 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01423 current scenarios/mysql/01-basics/autocommit-visibility.yaml:36 scenarios/mysql/01-basics/autocommit-visibility.yaml#steps[10].tl tl COMMIT M12 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01424 current scenarios/mysql/01-basics/autocommit-visibility.yaml:38 scenarios/mysql/01-basics/autocommit-visibility.yaml#steps[11].B B SELECT balance FROM accounts WHERE id = 1 M12 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01425 current scenarios/mysql/01-basics/autocommit-visibility.yaml:39 scenarios/mysql/01-basics/autocommit-visibility.yaml#steps[11].expect[0].balance balance 999 M12 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01426 current scenarios/mysql/01-basics/autocommit-visibility.yaml:40 scenarios/mysql/01-basics/autocommit-visibility.yaml#steps[11].tl tl SELECT balance → 999 (now visible) M12 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01427 current scenarios/mysql/01-basics/savepoint-nesting.yaml:1 scenarios/mysql/01-basics/savepoint-nesting.yaml#title title Nested savepoints and RELEASE M13 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01428 current scenarios/mysql/01-basics/savepoint-nesting.yaml:2 scenarios/mysql/01-basics/savepoint-nesting.yaml#claim claim Rolling back to an outer savepoint discards inner savepoints along with their work; RELEASE keeps the changes but forfeits the rollback point. M13 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01429 current scenarios/mysql/01-basics/savepoint-nesting.yaml:5 scenarios/mysql/01-basics/savepoint-nesting.yaml#setup setup "CREATE TABLE steps (n int PRIMARY KEY) ENGINE=InnoDB; " M13 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01430 current scenarios/mysql/01-basics/savepoint-nesting.yaml:7 scenarios/mysql/01-basics/savepoint-nesting.yaml#sessions[0] sessions[0] A M13 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01431 current scenarios/mysql/01-basics/savepoint-nesting.yaml:9 scenarios/mysql/01-basics/savepoint-nesting.yaml#steps[0].A A BEGIN M13 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01432 current scenarios/mysql/01-basics/savepoint-nesting.yaml:10 scenarios/mysql/01-basics/savepoint-nesting.yaml#steps[1].A A INSERT INTO steps VALUES (1) M13 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01433 current scenarios/mysql/01-basics/savepoint-nesting.yaml:11 scenarios/mysql/01-basics/savepoint-nesting.yaml#steps[2].A A SAVEPOINT outer_sp M13 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01434 current scenarios/mysql/01-basics/savepoint-nesting.yaml:12 scenarios/mysql/01-basics/savepoint-nesting.yaml#steps[3].A A INSERT INTO steps VALUES (2) M13 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01435 current scenarios/mysql/01-basics/savepoint-nesting.yaml:13 scenarios/mysql/01-basics/savepoint-nesting.yaml#steps[4].A A SAVEPOINT inner_sp M13 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01436 current scenarios/mysql/01-basics/savepoint-nesting.yaml:14 scenarios/mysql/01-basics/savepoint-nesting.yaml#steps[5].A A INSERT INTO steps VALUES (3) M13 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01437 current scenarios/mysql/01-basics/savepoint-nesting.yaml:16 scenarios/mysql/01-basics/savepoint-nesting.yaml#steps[6].note note Rolling back to the OUTER savepoint discards rows 2 and 3; and inner_sp itself. M13 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01438 current scenarios/mysql/01-basics/savepoint-nesting.yaml:17 scenarios/mysql/01-basics/savepoint-nesting.yaml#steps[7].A A ROLLBACK TO SAVEPOINT outer_sp M13 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01439 current scenarios/mysql/01-basics/savepoint-nesting.yaml:19 scenarios/mysql/01-basics/savepoint-nesting.yaml#steps[8].A.fails fails ROLLBACK TO SAVEPOINT inner_sp M13 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01440 current scenarios/mysql/01-basics/savepoint-nesting.yaml:20 scenarios/mysql/01-basics/savepoint-nesting.yaml#steps[8].error error 1305 M13 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01441 current scenarios/mysql/01-basics/savepoint-nesting.yaml:21 scenarios/mysql/01-basics/savepoint-nesting.yaml#steps[8].comment comment SAVEPOINT inner_sp does not exist; destroyed by the outer rollback M13 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01442 current scenarios/mysql/01-basics/savepoint-nesting.yaml:23 scenarios/mysql/01-basics/savepoint-nesting.yaml#steps[9].note note RELEASE keeps the work done after the savepoint, but you can no longer rewind to it. M13 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01443 current scenarios/mysql/01-basics/savepoint-nesting.yaml:24 scenarios/mysql/01-basics/savepoint-nesting.yaml#steps[10].A A INSERT INTO steps VALUES (4) M13 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01444 current scenarios/mysql/01-basics/savepoint-nesting.yaml:25 scenarios/mysql/01-basics/savepoint-nesting.yaml#steps[11].A A RELEASE SAVEPOINT outer_sp M13 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01445 current scenarios/mysql/01-basics/savepoint-nesting.yaml:26 scenarios/mysql/01-basics/savepoint-nesting.yaml#steps[12].A.fails fails ROLLBACK TO SAVEPOINT outer_sp M13 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01446 current scenarios/mysql/01-basics/savepoint-nesting.yaml:27 scenarios/mysql/01-basics/savepoint-nesting.yaml#steps[12].error error 1305 M13 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01447 current scenarios/mysql/01-basics/savepoint-nesting.yaml:28 scenarios/mysql/01-basics/savepoint-nesting.yaml#steps[12].comment comment the released savepoint no longer exists M13 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01448 current scenarios/mysql/01-basics/savepoint-nesting.yaml:29 scenarios/mysql/01-basics/savepoint-nesting.yaml#steps[13].A A COMMIT M13 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01449 current scenarios/mysql/01-basics/savepoint-nesting.yaml:31 scenarios/mysql/01-basics/savepoint-nesting.yaml#steps[14].A A SELECT n FROM steps ORDER BY n M13 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01450 current scenarios/mysql/01-basics/savepoint-nesting.yaml:32 scenarios/mysql/01-basics/savepoint-nesting.yaml#steps[14].expect[0].n n 1 M13 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01451 current scenarios/mysql/01-basics/savepoint-nesting.yaml:32 scenarios/mysql/01-basics/savepoint-nesting.yaml#steps[14].expect[1].n n 4 M13 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01452 current scenarios/mysql/01-basics/savepoint-recovery.yaml:1 scenarios/mysql/01-basics/savepoint-recovery.yaml#title title Savepoints: discard a risky branch mid-transaction M14 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01453 current scenarios/mysql/01-basics/savepoint-recovery.yaml:2 scenarios/mysql/01-basics/savepoint-recovery.yaml#claim claim In this InnoDB INSERT branch, ROLLBACK TO SAVEPOINT removes the successful branch INSERT after a 1062 error, preserves the earlier INSERT, and allows the replacement branch to commit. M14 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01454 current scenarios/mysql/01-basics/savepoint-recovery.yaml:6 scenarios/mysql/01-basics/savepoint-recovery.yaml#setup setup "CREATE TABLE items (id int PRIMARY KEY, name varchar(50) NOT NULL UNIQUE) ENGINE=InnoDB; INSERT INTO items VALUES (1, 'widget'); " M14 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01455 current scenarios/mysql/01-basics/savepoint-recovery.yaml:9 scenarios/mysql/01-basics/savepoint-recovery.yaml#sessions[0] sessions[0] A M14 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01456 current scenarios/mysql/01-basics/savepoint-recovery.yaml:11 scenarios/mysql/01-basics/savepoint-recovery.yaml#steps[0].A A BEGIN M14 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01457 current scenarios/mysql/01-basics/savepoint-recovery.yaml:12 scenarios/mysql/01-basics/savepoint-recovery.yaml#steps[1].A A INSERT INTO items VALUES (2, 'gadget') M14 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01458 current scenarios/mysql/01-basics/savepoint-recovery.yaml:13 scenarios/mysql/01-basics/savepoint-recovery.yaml#steps[2].A A SAVEPOINT before_risky M14 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01459 current scenarios/mysql/01-basics/savepoint-recovery.yaml:15 scenarios/mysql/01-basics/savepoint-recovery.yaml#steps[3].note note The risky branch makes real progress before it fails… M14 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01460 current scenarios/mysql/01-basics/savepoint-recovery.yaml:16 scenarios/mysql/01-basics/savepoint-recovery.yaml#steps[4].A A INSERT INTO items VALUES (3, 'gizmo') M14 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01461 current scenarios/mysql/01-basics/savepoint-recovery.yaml:17 scenarios/mysql/01-basics/savepoint-recovery.yaml#steps[5].A.fails fails INSERT INTO items VALUES (4, 'widget') M14 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01462 current scenarios/mysql/01-basics/savepoint-recovery.yaml:18 scenarios/mysql/01-basics/savepoint-recovery.yaml#steps[5].error error 1062 M14 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01463 current scenarios/mysql/01-basics/savepoint-recovery.yaml:19 scenarios/mysql/01-basics/savepoint-recovery.yaml#steps[5].comment comment ER_DUP_ENTRY M14 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01464 current scenarios/mysql/01-basics/savepoint-recovery.yaml:21 scenarios/mysql/01-basics/savepoint-recovery.yaml#steps[6].note note The transaction is still alive; but the branch is half-done. Rewind all of it in one go. M14 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01465 current scenarios/mysql/01-basics/savepoint-recovery.yaml:22 scenarios/mysql/01-basics/savepoint-recovery.yaml#steps[7].A A ROLLBACK TO SAVEPOINT before_risky M14 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01466 current scenarios/mysql/01-basics/savepoint-recovery.yaml:23 scenarios/mysql/01-basics/savepoint-recovery.yaml#steps[8].A A SELECT id, name FROM items ORDER BY id M14 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01467 current scenarios/mysql/01-basics/savepoint-recovery.yaml:24 scenarios/mysql/01-basics/savepoint-recovery.yaml#steps[8].expect[0].id id 1 M14 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01468 current scenarios/mysql/01-basics/savepoint-recovery.yaml:24 scenarios/mysql/01-basics/savepoint-recovery.yaml#steps[8].expect[0].name name widget M14 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01469 current scenarios/mysql/01-basics/savepoint-recovery.yaml:24 scenarios/mysql/01-basics/savepoint-recovery.yaml#steps[8].expect[1].id id 2 M14 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01470 current scenarios/mysql/01-basics/savepoint-recovery.yaml:24 scenarios/mysql/01-basics/savepoint-recovery.yaml#steps[8].expect[1].name name gadget M14 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01471 current scenarios/mysql/01-basics/savepoint-recovery.yaml:25 scenarios/mysql/01-basics/savepoint-recovery.yaml#steps[9].A A INSERT INTO items VALUES (3, 'doohickey') M14 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01472 current scenarios/mysql/01-basics/savepoint-recovery.yaml:26 scenarios/mysql/01-basics/savepoint-recovery.yaml#steps[10].A A COMMIT M14 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01473 current scenarios/mysql/01-basics/savepoint-recovery.yaml:28 scenarios/mysql/01-basics/savepoint-recovery.yaml#steps[11].A A SELECT id, name FROM items ORDER BY id M14 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01474 current scenarios/mysql/01-basics/savepoint-recovery.yaml:30 scenarios/mysql/01-basics/savepoint-recovery.yaml#steps[11].expect[0].id id 1 M14 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01475 current scenarios/mysql/01-basics/savepoint-recovery.yaml:30 scenarios/mysql/01-basics/savepoint-recovery.yaml#steps[11].expect[0].name name widget M14 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01476 current scenarios/mysql/01-basics/savepoint-recovery.yaml:31 scenarios/mysql/01-basics/savepoint-recovery.yaml#steps[11].expect[1].id id 2 M14 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01477 current scenarios/mysql/01-basics/savepoint-recovery.yaml:31 scenarios/mysql/01-basics/savepoint-recovery.yaml#steps[11].expect[1].name name gadget M14 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01478 current scenarios/mysql/01-basics/savepoint-recovery.yaml:32 scenarios/mysql/01-basics/savepoint-recovery.yaml#steps[11].expect[2].id id 3 M14 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01479 current scenarios/mysql/01-basics/savepoint-recovery.yaml:32 scenarios/mysql/01-basics/savepoint-recovery.yaml#steps[11].expect[2].name name doohickey M14 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01480 current scenarios/mysql/01-basics/savepoint-recovery.yaml:33 scenarios/mysql/01-basics/savepoint-recovery.yaml#steps[11].comment comment survived; it predates the savepoint; 'gizmo' is gone with the branch M14 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01481 current scenarios/mysql/02-isolation/circular-information-flow.yaml:1 scenarios/mysql/02-isolation/circular-information-flow.yaml#title title Circular information flow at READ UNCOMMITTED M15 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01482 current scenarios/mysql/02-isolation/circular-information-flow.yaml:2 scenarios/mysql/02-isolation/circular-information-flow.yaml#claim claim "At READ UNCOMMITTED two concurrent transactions can each read the other's uncommitted write (Adya's G1c, ""circular information flow""); an exchange no serial order can explain. The repeated READ COMMITTED schedule excludes those dirty cross-reads, but its two old reads do not prove serializability." M15 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01483 current scenarios/mysql/02-isolation/circular-information-flow.yaml:7 scenarios/mysql/02-isolation/circular-information-flow.yaml#anomaly anomaly G1c M15 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01484 current scenarios/mysql/02-isolation/circular-information-flow.yaml:8 scenarios/mysql/02-isolation/circular-information-flow.yaml#setup setup "CREATE TABLE accounts (id int PRIMARY KEY, owner varchar(20) NOT NULL, balance int NOT NULL) ENGINE=InnoDB; INSERT INTO accounts VALUES (1, 'alice', 100), (2, 'bob', 100); " M15 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01485 current scenarios/mysql/02-isolation/circular-information-flow.yaml:11 scenarios/mysql/02-isolation/circular-information-flow.yaml#sessions[0] sessions[0] A M15 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01486 current scenarios/mysql/02-isolation/circular-information-flow.yaml:11 scenarios/mysql/02-isolation/circular-information-flow.yaml#sessions[1] sessions[1] B M15 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01487 current scenarios/mysql/02-isolation/circular-information-flow.yaml:13 scenarios/mysql/02-isolation/circular-information-flow.yaml#steps[0].note note A adjusts alice while B adjusts bob; then each peeks at the other's row. In any serial order, at most one of them can see the other's write. M15 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01488 current scenarios/mysql/02-isolation/circular-information-flow.yaml:16 scenarios/mysql/02-isolation/circular-information-flow.yaml#steps[1].A A SET SESSION TRANSACTION ISOLATION LEVEL READ UNCOMMITTED M15 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ UNCOMMITTED, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01489 current scenarios/mysql/02-isolation/circular-information-flow.yaml:17 scenarios/mysql/02-isolation/circular-information-flow.yaml#steps[2].B B SET SESSION TRANSACTION ISOLATION LEVEL READ UNCOMMITTED M15 MySQL 8.4.11, InnoDB; before step: A=READ UNCOMMITTED, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ UNCOMMITTED, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01490 current scenarios/mysql/02-isolation/circular-information-flow.yaml:18 scenarios/mysql/02-isolation/circular-information-flow.yaml#steps[3].A A BEGIN M15 MySQL 8.4.11, InnoDB; before step: A=READ UNCOMMITTED, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ UNCOMMITTED, open transaction, autocommit=1; B=READ UNCOMMITTED, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01491 current scenarios/mysql/02-isolation/circular-information-flow.yaml:19 scenarios/mysql/02-isolation/circular-information-flow.yaml#steps[4].B B BEGIN M15 MySQL 8.4.11, InnoDB; before step: A=READ UNCOMMITTED, open transaction, autocommit=1; B=READ UNCOMMITTED, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ UNCOMMITTED, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01492 current scenarios/mysql/02-isolation/circular-information-flow.yaml:20 scenarios/mysql/02-isolation/circular-information-flow.yaml#steps[5].A A UPDATE accounts SET balance = 111 WHERE id = 1 M15 MySQL 8.4.11, InnoDB; before step: A=READ UNCOMMITTED, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=READ UNCOMMITTED, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01493 current scenarios/mysql/02-isolation/circular-information-flow.yaml:21 scenarios/mysql/02-isolation/circular-information-flow.yaml#steps[5].tl tl UPDATE alice = 111 (uncommitted) M15 MySQL 8.4.11, InnoDB; before step: A=READ UNCOMMITTED, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=READ UNCOMMITTED, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01494 current scenarios/mysql/02-isolation/circular-information-flow.yaml:22 scenarios/mysql/02-isolation/circular-information-flow.yaml#steps[6].B B UPDATE accounts SET balance = 222 WHERE id = 2 M15 MySQL 8.4.11, InnoDB; before step: A=READ UNCOMMITTED, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=READ UNCOMMITTED, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01495 current scenarios/mysql/02-isolation/circular-information-flow.yaml:23 scenarios/mysql/02-isolation/circular-information-flow.yaml#steps[6].tl tl UPDATE bob = 222 (uncommitted) M15 MySQL 8.4.11, InnoDB; before step: A=READ UNCOMMITTED, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=READ UNCOMMITTED, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01496 current scenarios/mysql/02-isolation/circular-information-flow.yaml:25 scenarios/mysql/02-isolation/circular-information-flow.yaml#steps[7].A A SELECT balance FROM accounts WHERE id = 2 M15 MySQL 8.4.11, InnoDB; before step: A=READ UNCOMMITTED, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=READ UNCOMMITTED, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01497 current scenarios/mysql/02-isolation/circular-information-flow.yaml:26 scenarios/mysql/02-isolation/circular-information-flow.yaml#steps[7].expect[0].balance balance 222 M15 MySQL 8.4.11, InnoDB; before step: A=READ UNCOMMITTED, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=READ UNCOMMITTED, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01498 current scenarios/mysql/02-isolation/circular-information-flow.yaml:27 scenarios/mysql/02-isolation/circular-information-flow.yaml#steps[7].comment comment A sees B's uncommitted write… M15 MySQL 8.4.11, InnoDB; before step: A=READ UNCOMMITTED, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=READ UNCOMMITTED, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01499 current scenarios/mysql/02-isolation/circular-information-flow.yaml:28 scenarios/mysql/02-isolation/circular-information-flow.yaml#steps[7].tl tl read bob → 222 (B's uncommitted) M15 MySQL 8.4.11, InnoDB; before step: A=READ UNCOMMITTED, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=READ UNCOMMITTED, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01500 current scenarios/mysql/02-isolation/circular-information-flow.yaml:29 scenarios/mysql/02-isolation/circular-information-flow.yaml#steps[8].B B SELECT balance FROM accounts WHERE id = 1 M15 MySQL 8.4.11, InnoDB; before step: A=READ UNCOMMITTED, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=READ UNCOMMITTED, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01501 current scenarios/mysql/02-isolation/circular-information-flow.yaml:30 scenarios/mysql/02-isolation/circular-information-flow.yaml#steps[8].expect[0].balance balance 111 M15 MySQL 8.4.11, InnoDB; before step: A=READ UNCOMMITTED, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=READ UNCOMMITTED, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01502 current scenarios/mysql/02-isolation/circular-information-flow.yaml:31 scenarios/mysql/02-isolation/circular-information-flow.yaml#steps[8].comment comment …and B sees A's. Information flowed in a circle. M15 MySQL 8.4.11, InnoDB; before step: A=READ UNCOMMITTED, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=READ UNCOMMITTED, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01503 current scenarios/mysql/02-isolation/circular-information-flow.yaml:32 scenarios/mysql/02-isolation/circular-information-flow.yaml#steps[8].tl tl read alice → 111 (A's uncommitted) M15 MySQL 8.4.11, InnoDB; before step: A=READ UNCOMMITTED, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=READ UNCOMMITTED, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01504 current scenarios/mysql/02-isolation/circular-information-flow.yaml:34 scenarios/mysql/02-isolation/circular-information-flow.yaml#steps[9].note note Both dirty cross-reads are asserted, then both writers commit. No serial order of these two transactions gives both new values to the readers. No external application arithmetic is executed. M15 MySQL 8.4.11, InnoDB; before step: A=READ UNCOMMITTED, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=READ UNCOMMITTED, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01505 current scenarios/mysql/02-isolation/circular-information-flow.yaml:38 scenarios/mysql/02-isolation/circular-information-flow.yaml#steps[10].A A COMMIT M15 MySQL 8.4.11, InnoDB; before step: A=READ UNCOMMITTED, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=READ UNCOMMITTED, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01506 current scenarios/mysql/02-isolation/circular-information-flow.yaml:39 scenarios/mysql/02-isolation/circular-information-flow.yaml#steps[10].tl tl COMMIT M15 MySQL 8.4.11, InnoDB; before step: A=READ UNCOMMITTED, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=READ UNCOMMITTED, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01507 current scenarios/mysql/02-isolation/circular-information-flow.yaml:40 scenarios/mysql/02-isolation/circular-information-flow.yaml#steps[11].B B COMMIT M15 MySQL 8.4.11, InnoDB; before step: A=READ UNCOMMITTED, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=READ UNCOMMITTED, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01508 current scenarios/mysql/02-isolation/circular-information-flow.yaml:41 scenarios/mysql/02-isolation/circular-information-flow.yaml#steps[11].tl tl COMMIT M15 MySQL 8.4.11, InnoDB; before step: A=READ UNCOMMITTED, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=READ UNCOMMITTED, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01509 current scenarios/mysql/02-isolation/circular-information-flow.yaml:42 scenarios/mysql/02-isolation/circular-information-flow.yaml#steps[12].A A SELECT id, balance FROM accounts ORDER BY id M15 MySQL 8.4.11, InnoDB; before step: A=READ UNCOMMITTED, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ UNCOMMITTED, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01510 current scenarios/mysql/02-isolation/circular-information-flow.yaml:43 scenarios/mysql/02-isolation/circular-information-flow.yaml#steps[12].expect[0].id id 1 M15 MySQL 8.4.11, InnoDB; before step: A=READ UNCOMMITTED, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ UNCOMMITTED, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01511 current scenarios/mysql/02-isolation/circular-information-flow.yaml:43 scenarios/mysql/02-isolation/circular-information-flow.yaml#steps[12].expect[0].balance balance 111 M15 MySQL 8.4.11, InnoDB; before step: A=READ UNCOMMITTED, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ UNCOMMITTED, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01512 current scenarios/mysql/02-isolation/circular-information-flow.yaml:43 scenarios/mysql/02-isolation/circular-information-flow.yaml#steps[12].expect[1].id id 2 M15 MySQL 8.4.11, InnoDB; before step: A=READ UNCOMMITTED, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ UNCOMMITTED, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01513 current scenarios/mysql/02-isolation/circular-information-flow.yaml:43 scenarios/mysql/02-isolation/circular-information-flow.yaml#steps[12].expect[1].balance balance 222 M15 MySQL 8.4.11, InnoDB; before step: A=READ UNCOMMITTED, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ UNCOMMITTED, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01514 current scenarios/mysql/02-isolation/circular-information-flow.yaml:44 scenarios/mysql/02-isolation/circular-information-flow.yaml#steps[13].A A UPDATE accounts SET balance = 100 M15 MySQL 8.4.11, InnoDB; before step: A=READ UNCOMMITTED, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ UNCOMMITTED, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01515 current scenarios/mysql/02-isolation/circular-information-flow.yaml:46 scenarios/mysql/02-isolation/circular-information-flow.yaml#steps[14].note note After resetting both balances, READ COMMITTED excludes these dirty cross-reads. The two old reads still do not form a serial execution. M15 MySQL 8.4.11, InnoDB; before step: A=READ UNCOMMITTED, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ UNCOMMITTED, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01516 current scenarios/mysql/02-isolation/circular-information-flow.yaml:47 scenarios/mysql/02-isolation/circular-information-flow.yaml#steps[15].A A SET SESSION TRANSACTION ISOLATION LEVEL READ COMMITTED M15 MySQL 8.4.11, InnoDB; before step: A=READ UNCOMMITTED, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01517 current scenarios/mysql/02-isolation/circular-information-flow.yaml:48 scenarios/mysql/02-isolation/circular-information-flow.yaml#steps[16].B B SET SESSION TRANSACTION ISOLATION LEVEL READ COMMITTED M15 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, standalone/next transaction, autocommit=1; B=READ COMMITTED, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01518 current scenarios/mysql/02-isolation/circular-information-flow.yaml:49 scenarios/mysql/02-isolation/circular-information-flow.yaml#steps[17].A A BEGIN M15 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, standalone/next transaction, autocommit=1; B=READ COMMITTED, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, open transaction, autocommit=1; B=READ COMMITTED, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01519 current scenarios/mysql/02-isolation/circular-information-flow.yaml:50 scenarios/mysql/02-isolation/circular-information-flow.yaml#steps[18].B B BEGIN M15 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, open transaction, autocommit=1; B=READ COMMITTED, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, open transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01520 current scenarios/mysql/02-isolation/circular-information-flow.yaml:51 scenarios/mysql/02-isolation/circular-information-flow.yaml#steps[19].A A UPDATE accounts SET balance = 111 WHERE id = 1 M15 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, open transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, open transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01521 current scenarios/mysql/02-isolation/circular-information-flow.yaml:52 scenarios/mysql/02-isolation/circular-information-flow.yaml#steps[20].B B UPDATE accounts SET balance = 222 WHERE id = 2 M15 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, open transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, open transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01522 current scenarios/mysql/02-isolation/circular-information-flow.yaml:53 scenarios/mysql/02-isolation/circular-information-flow.yaml#steps[21].A A SELECT balance FROM accounts WHERE id = 2 M15 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, open transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, open transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01523 current scenarios/mysql/02-isolation/circular-information-flow.yaml:54 scenarios/mysql/02-isolation/circular-information-flow.yaml#steps[21].expect[0].balance balance 100 M15 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, open transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, open transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01524 current scenarios/mysql/02-isolation/circular-information-flow.yaml:55 scenarios/mysql/02-isolation/circular-information-flow.yaml#steps[22].B B SELECT balance FROM accounts WHERE id = 1 M15 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, open transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, open transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01525 current scenarios/mysql/02-isolation/circular-information-flow.yaml:56 scenarios/mysql/02-isolation/circular-information-flow.yaml#steps[22].expect[0].balance balance 100 M15 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, open transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, open transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01526 current scenarios/mysql/02-isolation/circular-information-flow.yaml:57 scenarios/mysql/02-isolation/circular-information-flow.yaml#steps[23].A A COMMIT M15 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, open transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, standalone/next transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01527 current scenarios/mysql/02-isolation/circular-information-flow.yaml:58 scenarios/mysql/02-isolation/circular-information-flow.yaml#steps[24].B B COMMIT M15 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, standalone/next transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, standalone/next transaction, autocommit=1; B=READ COMMITTED, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01528 current scenarios/mysql/02-isolation/current-reads.yaml:1 scenarios/mysql/02-isolation/current-reads.yaml#title title Current reads punch holes in the snapshot M16 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01529 current scenarios/mysql/02-isolation/current-reads.yaml:2 scenarios/mysql/02-isolation/current-reads.yaml#claim claim In this InnoDB REPEATABLE READ schedule, A's UPDATE computes from B's committed 150, not its snapshot's 100, and A reads its own result 200. In the second attempt A waits for B's commit of 300 and produces 350. M16 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01530 current scenarios/mysql/02-isolation/current-reads.yaml:6 scenarios/mysql/02-isolation/current-reads.yaml#setup setup "CREATE TABLE accounts (id int PRIMARY KEY, owner varchar(20) NOT NULL, balance int NOT NULL) ENGINE=InnoDB; INSERT INTO accounts VALUES (1, 'alice', 100); " M16 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01531 current scenarios/mysql/02-isolation/current-reads.yaml:9 scenarios/mysql/02-isolation/current-reads.yaml#sessions[0] sessions[0] A M16 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01532 current scenarios/mysql/02-isolation/current-reads.yaml:9 scenarios/mysql/02-isolation/current-reads.yaml#sessions[1] sessions[1] B M16 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01533 current scenarios/mysql/02-isolation/current-reads.yaml:11 scenarios/mysql/02-isolation/current-reads.yaml#steps[0].A A SET SESSION TRANSACTION ISOLATION LEVEL REPEATABLE READ M16 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01534 current scenarios/mysql/02-isolation/current-reads.yaml:12 scenarios/mysql/02-isolation/current-reads.yaml#steps[1].A A BEGIN M16 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01535 current scenarios/mysql/02-isolation/current-reads.yaml:13 scenarios/mysql/02-isolation/current-reads.yaml#steps[2].A A SELECT balance FROM accounts WHERE id = 1 M16 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01536 current scenarios/mysql/02-isolation/current-reads.yaml:14 scenarios/mysql/02-isolation/current-reads.yaml#steps[2].expect[0].balance balance 100 M16 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01537 current scenarios/mysql/02-isolation/current-reads.yaml:15 scenarios/mysql/02-isolation/current-reads.yaml#steps[2].comment comment snapshot taken M16 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01538 current scenarios/mysql/02-isolation/current-reads.yaml:16 scenarios/mysql/02-isolation/current-reads.yaml#steps[2].tl tl SELECT balance → 100 (snapshot) M16 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01539 current scenarios/mysql/02-isolation/current-reads.yaml:18 scenarios/mysql/02-isolation/current-reads.yaml#steps[3].note note B commits a change. A keeps READING its stale snapshot… M16 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01540 current scenarios/mysql/02-isolation/current-reads.yaml:19 scenarios/mysql/02-isolation/current-reads.yaml#steps[4].B B UPDATE accounts SET balance = 150 WHERE id = 1 M16 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01541 current scenarios/mysql/02-isolation/current-reads.yaml:20 scenarios/mysql/02-isolation/current-reads.yaml#steps[4].tl tl UPDATE balance = 150 (committed) M16 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01542 current scenarios/mysql/02-isolation/current-reads.yaml:22 scenarios/mysql/02-isolation/current-reads.yaml#steps[5].A A SELECT balance FROM accounts WHERE id = 1 M16 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01543 current scenarios/mysql/02-isolation/current-reads.yaml:23 scenarios/mysql/02-isolation/current-reads.yaml#steps[5].expect[0].balance balance 100 M16 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01544 current scenarios/mysql/02-isolation/current-reads.yaml:24 scenarios/mysql/02-isolation/current-reads.yaml#steps[5].tl tl SELECT balance → 100 (snapshot holds) M16 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01545 current scenarios/mysql/02-isolation/current-reads.yaml:26 scenarios/mysql/02-isolation/current-reads.yaml#steps[6].note note …but A's UPDATE is a current read: it computes from B's committed 150, not from the snapshot's 100. M16 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01546 current scenarios/mysql/02-isolation/current-reads.yaml:29 scenarios/mysql/02-isolation/current-reads.yaml#steps[7].A A UPDATE accounts SET balance = balance + 50 WHERE id = 1 M16 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01547 current scenarios/mysql/02-isolation/current-reads.yaml:30 scenarios/mysql/02-isolation/current-reads.yaml#steps[7].tl tl UPDATE +50 (current read of 150) M16 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01548 current scenarios/mysql/02-isolation/current-reads.yaml:32 scenarios/mysql/02-isolation/current-reads.yaml#steps[8].A A SELECT balance FROM accounts WHERE id = 1 M16 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01549 current scenarios/mysql/02-isolation/current-reads.yaml:33 scenarios/mysql/02-isolation/current-reads.yaml#steps[8].expect[0].balance balance 200 M16 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01550 current scenarios/mysql/02-isolation/current-reads.yaml:34 scenarios/mysql/02-isolation/current-reads.yaml#steps[8].comment comment 150 + 50; and now A sees it: the snapshot has a hole M16 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01551 current scenarios/mysql/02-isolation/current-reads.yaml:35 scenarios/mysql/02-isolation/current-reads.yaml#steps[8].tl tl SELECT balance → 200 (150 + 50; the hole) M16 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01552 current scenarios/mysql/02-isolation/current-reads.yaml:37 scenarios/mysql/02-isolation/current-reads.yaml#steps[9].A A COMMIT M16 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01553 current scenarios/mysql/02-isolation/current-reads.yaml:38 scenarios/mysql/02-isolation/current-reads.yaml#steps[9].tl tl COMMIT M16 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01554 current scenarios/mysql/02-isolation/current-reads.yaml:39 scenarios/mysql/02-isolation/current-reads.yaml#steps[10].note note A's own write is visible to its later consistent SELECT. The PostgreSQL comparison is in its concurrent-update lesson. M16 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01555 current scenarios/mysql/02-isolation/current-reads.yaml:41 scenarios/mysql/02-isolation/current-reads.yaml#steps[11].note note If the competing write is NOT yet committed, A first waits on the row lock… M16 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01556 current scenarios/mysql/02-isolation/current-reads.yaml:42 scenarios/mysql/02-isolation/current-reads.yaml#steps[12].A A BEGIN M16 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01557 current scenarios/mysql/02-isolation/current-reads.yaml:43 scenarios/mysql/02-isolation/current-reads.yaml#steps[13].A A SELECT balance FROM accounts WHERE id = 1 M16 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01558 current scenarios/mysql/02-isolation/current-reads.yaml:44 scenarios/mysql/02-isolation/current-reads.yaml#steps[13].expect[0].balance balance 200 M16 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01559 current scenarios/mysql/02-isolation/current-reads.yaml:45 scenarios/mysql/02-isolation/current-reads.yaml#steps[13].comment comment snapshot taken M16 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01560 current scenarios/mysql/02-isolation/current-reads.yaml:47 scenarios/mysql/02-isolation/current-reads.yaml#steps[14].B B BEGIN M16 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01561 current scenarios/mysql/02-isolation/current-reads.yaml:48 scenarios/mysql/02-isolation/current-reads.yaml#steps[15].B B UPDATE accounts SET balance = 300 WHERE id = 1 M16 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01562 current scenarios/mysql/02-isolation/current-reads.yaml:50 scenarios/mysql/02-isolation/current-reads.yaml#steps[16].A A UPDATE accounts SET balance = balance + 50 WHERE id = 1 M16 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01563 current scenarios/mysql/02-isolation/current-reads.yaml:51 scenarios/mysql/02-isolation/current-reads.yaml#steps[16].blocks blocks p1 M16 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01564 current scenarios/mysql/02-isolation/current-reads.yaml:53 scenarios/mysql/02-isolation/current-reads.yaml#steps[17].note note …and proceeds from B's value the moment B commits. No error here either. M16 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01565 current scenarios/mysql/02-isolation/current-reads.yaml:54 scenarios/mysql/02-isolation/current-reads.yaml#steps[18].B B COMMIT M16 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01566 current scenarios/mysql/02-isolation/current-reads.yaml:56 scenarios/mysql/02-isolation/current-reads.yaml#steps[19].success success p1 M16 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01567 current scenarios/mysql/02-isolation/current-reads.yaml:57 scenarios/mysql/02-isolation/current-reads.yaml#steps[20].A A SELECT balance FROM accounts WHERE id = 1 M16 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01568 current scenarios/mysql/02-isolation/current-reads.yaml:58 scenarios/mysql/02-isolation/current-reads.yaml#steps[20].expect[0].balance balance 350 M16 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01569 current scenarios/mysql/02-isolation/current-reads.yaml:59 scenarios/mysql/02-isolation/current-reads.yaml#steps[20].comment comment 300 + 50 M16 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01570 current scenarios/mysql/02-isolation/current-reads.yaml:60 scenarios/mysql/02-isolation/current-reads.yaml#steps[21].A A COMMIT M16 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01571 current scenarios/mysql/02-isolation/dirty-read.yaml:1 scenarios/mysql/02-isolation/dirty-read.yaml#title title READ UNCOMMITTED really reads uncommitted data M17 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01572 current scenarios/mysql/02-isolation/dirty-read.yaml:2 scenarios/mysql/02-isolation/dirty-read.yaml#claim claim At READ UNCOMMITTED, MySQL serves other transactions' uncommitted changes including the asserted 999 that A later rolls back. The value existed uncommitted, but never became part of committed history. M17 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01573 current scenarios/mysql/02-isolation/dirty-read.yaml:6 scenarios/mysql/02-isolation/dirty-read.yaml#anomaly anomaly G1a M17 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01574 current scenarios/mysql/02-isolation/dirty-read.yaml:7 scenarios/mysql/02-isolation/dirty-read.yaml#isolation isolation READ UNCOMMITTED M17 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01575 current scenarios/mysql/02-isolation/dirty-read.yaml:8 scenarios/mysql/02-isolation/dirty-read.yaml#setup setup "CREATE TABLE accounts (id int PRIMARY KEY, owner varchar(20) NOT NULL, balance int NOT NULL) ENGINE=InnoDB; INSERT INTO accounts VALUES (1, 'alice', 100); " M17 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01576 current scenarios/mysql/02-isolation/dirty-read.yaml:11 scenarios/mysql/02-isolation/dirty-read.yaml#sessions[0] sessions[0] A M17 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01577 current scenarios/mysql/02-isolation/dirty-read.yaml:11 scenarios/mysql/02-isolation/dirty-read.yaml#sessions[1] sessions[1] B M17 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01578 current scenarios/mysql/02-isolation/dirty-read.yaml:13 scenarios/mysql/02-isolation/dirty-read.yaml#steps[0].A A BEGIN M17 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01579 current scenarios/mysql/02-isolation/dirty-read.yaml:14 scenarios/mysql/02-isolation/dirty-read.yaml#steps[1].A A UPDATE accounts SET balance = 999 WHERE id = 1 M17 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01580 current scenarios/mysql/02-isolation/dirty-read.yaml:15 scenarios/mysql/02-isolation/dirty-read.yaml#steps[1].tl tl UPDATE balance = 999 (uncommitted) M17 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01581 current scenarios/mysql/02-isolation/dirty-read.yaml:17 scenarios/mysql/02-isolation/dirty-read.yaml#steps[2].note note B opts into READ UNCOMMITTED; and sees A's uncommitted 999. M17 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01582 current scenarios/mysql/02-isolation/dirty-read.yaml:18 scenarios/mysql/02-isolation/dirty-read.yaml#steps[3].B B SET SESSION TRANSACTION ISOLATION LEVEL READ UNCOMMITTED M17 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=READ UNCOMMITTED, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01583 current scenarios/mysql/02-isolation/dirty-read.yaml:19 scenarios/mysql/02-isolation/dirty-read.yaml#steps[4].B B BEGIN M17 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=READ UNCOMMITTED, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01584 current scenarios/mysql/02-isolation/dirty-read.yaml:21 scenarios/mysql/02-isolation/dirty-read.yaml#steps[5].B B SELECT @@transaction_isolation AS isolation M17 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01585 current scenarios/mysql/02-isolation/dirty-read.yaml:22 scenarios/mysql/02-isolation/dirty-read.yaml#steps[5].expect[0].isolation isolation READ-UNCOMMITTED M17 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01586 current scenarios/mysql/02-isolation/dirty-read.yaml:24 scenarios/mysql/02-isolation/dirty-read.yaml#steps[6].B B SELECT balance FROM accounts WHERE id = 1 M17 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01587 current scenarios/mysql/02-isolation/dirty-read.yaml:25 scenarios/mysql/02-isolation/dirty-read.yaml#steps[6].expect[0].balance balance 999 M17 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01588 current scenarios/mysql/02-isolation/dirty-read.yaml:26 scenarios/mysql/02-isolation/dirty-read.yaml#steps[6].comment comment a dirty read; A never committed this M17 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01589 current scenarios/mysql/02-isolation/dirty-read.yaml:27 scenarios/mysql/02-isolation/dirty-read.yaml#steps[6].tl tl SELECT balance → 999 (dirty read) M17 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01590 current scenarios/mysql/02-isolation/dirty-read.yaml:29 scenarios/mysql/02-isolation/dirty-read.yaml#steps[7].note note A rolls back. The 999 B read never became committed. M17 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01591 current scenarios/mysql/02-isolation/dirty-read.yaml:30 scenarios/mysql/02-isolation/dirty-read.yaml#steps[8].A A ROLLBACK M17 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01592 current scenarios/mysql/02-isolation/dirty-read.yaml:31 scenarios/mysql/02-isolation/dirty-read.yaml#steps[8].tl tl ROLLBACK; 999 never committed M17 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01593 current scenarios/mysql/02-isolation/dirty-read.yaml:33 scenarios/mysql/02-isolation/dirty-read.yaml#steps[9].B B SELECT balance FROM accounts WHERE id = 1 M17 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01594 current scenarios/mysql/02-isolation/dirty-read.yaml:34 scenarios/mysql/02-isolation/dirty-read.yaml#steps[9].expect[0].balance balance 100 M17 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01595 current scenarios/mysql/02-isolation/dirty-read.yaml:35 scenarios/mysql/02-isolation/dirty-read.yaml#steps[9].tl tl SELECT balance → 100 (the real value) M17 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01596 current scenarios/mysql/02-isolation/dirty-read.yaml:36 scenarios/mysql/02-isolation/dirty-read.yaml#steps[10].B B COMMIT M17 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01597 current scenarios/mysql/02-isolation/dirty-write.yaml:1 scenarios/mysql/02-isolation/dirty-write.yaml#title title A second writer waits at READ UNCOMMITTED M18 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01598 current scenarios/mysql/02-isolation/dirty-write.yaml:2 scenarios/mysql/02-isolation/dirty-write.yaml#claim claim In this InnoDB READ UNCOMMITTED schedule, B's UPDATE of A's uncommitted row waits until A commits. Both of B's later prices are asserted after B commits. All-level dirty-write exclusion needs the row-lock contract. M18 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01599 current scenarios/mysql/02-isolation/dirty-write.yaml:6 scenarios/mysql/02-isolation/dirty-write.yaml#anomaly anomaly G0 M18 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01600 current scenarios/mysql/02-isolation/dirty-write.yaml:7 scenarios/mysql/02-isolation/dirty-write.yaml#isolation isolation READ UNCOMMITTED M18 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01601 current scenarios/mysql/02-isolation/dirty-write.yaml:8 scenarios/mysql/02-isolation/dirty-write.yaml#setup setup "CREATE TABLE items (id int PRIMARY KEY, name varchar(20) NOT NULL, price int NOT NULL) ENGINE=InnoDB; INSERT INTO items VALUES (1, 'mug', 10), (2, 'cap', 20); " M18 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01602 current scenarios/mysql/02-isolation/dirty-write.yaml:11 scenarios/mysql/02-isolation/dirty-write.yaml#sessions[0] sessions[0] A M18 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01603 current scenarios/mysql/02-isolation/dirty-write.yaml:11 scenarios/mysql/02-isolation/dirty-write.yaml#sessions[1] sessions[1] B M18 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01604 current scenarios/mysql/02-isolation/dirty-write.yaml:13 scenarios/mysql/02-isolation/dirty-write.yaml#steps[0].note note Two batch jobs reprice the whole catalog concurrently at READ UNCOMMITTED. The dirty-write event would be overwriting A's uncommitted row; a mixed final state is not its definition. M18 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01605 current scenarios/mysql/02-isolation/dirty-write.yaml:17 scenarios/mysql/02-isolation/dirty-write.yaml#steps[1].A A SET SESSION TRANSACTION ISOLATION LEVEL READ UNCOMMITTED M18 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ UNCOMMITTED, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01606 current scenarios/mysql/02-isolation/dirty-write.yaml:18 scenarios/mysql/02-isolation/dirty-write.yaml#steps[2].B B SET SESSION TRANSACTION ISOLATION LEVEL READ UNCOMMITTED M18 MySQL 8.4.11, InnoDB; before step: A=READ UNCOMMITTED, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ UNCOMMITTED, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01607 current scenarios/mysql/02-isolation/dirty-write.yaml:19 scenarios/mysql/02-isolation/dirty-write.yaml#steps[3].A A BEGIN M18 MySQL 8.4.11, InnoDB; before step: A=READ UNCOMMITTED, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ UNCOMMITTED, open transaction, autocommit=1; B=READ UNCOMMITTED, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01608 current scenarios/mysql/02-isolation/dirty-write.yaml:20 scenarios/mysql/02-isolation/dirty-write.yaml#steps[4].B B BEGIN M18 MySQL 8.4.11, InnoDB; before step: A=READ UNCOMMITTED, open transaction, autocommit=1; B=READ UNCOMMITTED, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ UNCOMMITTED, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01609 current scenarios/mysql/02-isolation/dirty-write.yaml:21 scenarios/mysql/02-isolation/dirty-write.yaml#steps[5].A A UPDATE items SET price = 11 WHERE id = 1 M18 MySQL 8.4.11, InnoDB; before step: A=READ UNCOMMITTED, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=READ UNCOMMITTED, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01610 current scenarios/mysql/02-isolation/dirty-write.yaml:22 scenarios/mysql/02-isolation/dirty-write.yaml#steps[5].tl tl UPDATE mug = 11 M18 MySQL 8.4.11, InnoDB; before step: A=READ UNCOMMITTED, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=READ UNCOMMITTED, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01611 current scenarios/mysql/02-isolation/dirty-write.yaml:24 scenarios/mysql/02-isolation/dirty-write.yaml#steps[6].note note B may READ A's uncommitted rows at this level; but it may not overwrite them. M18 MySQL 8.4.11, InnoDB; before step: A=READ UNCOMMITTED, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=READ UNCOMMITTED, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01612 current scenarios/mysql/02-isolation/dirty-write.yaml:25 scenarios/mysql/02-isolation/dirty-write.yaml#steps[7].B B UPDATE items SET price = 12 WHERE id = 1 M18 MySQL 8.4.11, InnoDB; before step: A=READ UNCOMMITTED, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=READ UNCOMMITTED, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01613 current scenarios/mysql/02-isolation/dirty-write.yaml:26 scenarios/mysql/02-isolation/dirty-write.yaml#steps[7].blocks blocks p1 M18 MySQL 8.4.11, InnoDB; before step: A=READ UNCOMMITTED, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=READ UNCOMMITTED, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01614 current scenarios/mysql/02-isolation/dirty-write.yaml:27 scenarios/mysql/02-isolation/dirty-write.yaml#steps[7].tl tl UPDATE mug = 12 M18 MySQL 8.4.11, InnoDB; before step: A=READ UNCOMMITTED, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=READ UNCOMMITTED, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01615 current scenarios/mysql/02-isolation/dirty-write.yaml:29 scenarios/mysql/02-isolation/dirty-write.yaml#steps[8].A A UPDATE items SET price = 21 WHERE id = 2 M18 MySQL 8.4.11, InnoDB; before step: A=READ UNCOMMITTED, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=READ UNCOMMITTED, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01616 current scenarios/mysql/02-isolation/dirty-write.yaml:30 scenarios/mysql/02-isolation/dirty-write.yaml#steps[8].tl tl UPDATE cap = 21 M18 MySQL 8.4.11, InnoDB; before step: A=READ UNCOMMITTED, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=READ UNCOMMITTED, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01617 current scenarios/mysql/02-isolation/dirty-write.yaml:31 scenarios/mysql/02-isolation/dirty-write.yaml#steps[9].A A COMMIT M18 MySQL 8.4.11, InnoDB; before step: A=READ UNCOMMITTED, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=READ UNCOMMITTED, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01618 current scenarios/mysql/02-isolation/dirty-write.yaml:32 scenarios/mysql/02-isolation/dirty-write.yaml#steps[9].comment comment releases both row locks M18 MySQL 8.4.11, InnoDB; before step: A=READ UNCOMMITTED, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=READ UNCOMMITTED, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01619 current scenarios/mysql/02-isolation/dirty-write.yaml:33 scenarios/mysql/02-isolation/dirty-write.yaml#steps[9].tl tl COMMIT M18 MySQL 8.4.11, InnoDB; before step: A=READ UNCOMMITTED, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=READ UNCOMMITTED, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01620 current scenarios/mysql/02-isolation/dirty-write.yaml:34 scenarios/mysql/02-isolation/dirty-write.yaml#steps[10].success success p1 M18 MySQL 8.4.11, InnoDB; before step: A=READ UNCOMMITTED, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=READ UNCOMMITTED, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01621 current scenarios/mysql/02-isolation/dirty-write.yaml:36 scenarios/mysql/02-isolation/dirty-write.yaml#steps[11].B B UPDATE items SET price = 22 WHERE id = 2 M18 MySQL 8.4.11, InnoDB; before step: A=READ UNCOMMITTED, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=READ UNCOMMITTED, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01622 current scenarios/mysql/02-isolation/dirty-write.yaml:37 scenarios/mysql/02-isolation/dirty-write.yaml#steps[11].tl tl UPDATE cap = 22 M18 MySQL 8.4.11, InnoDB; before step: A=READ UNCOMMITTED, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=READ UNCOMMITTED, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01623 current scenarios/mysql/02-isolation/dirty-write.yaml:38 scenarios/mysql/02-isolation/dirty-write.yaml#steps[12].B B COMMIT M18 MySQL 8.4.11, InnoDB; before step: A=READ UNCOMMITTED, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=READ UNCOMMITTED, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01624 current scenarios/mysql/02-isolation/dirty-write.yaml:39 scenarios/mysql/02-isolation/dirty-write.yaml#steps[12].tl tl COMMIT M18 MySQL 8.4.11, InnoDB; before step: A=READ UNCOMMITTED, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=READ UNCOMMITTED, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01625 current scenarios/mysql/02-isolation/dirty-write.yaml:41 scenarios/mysql/02-isolation/dirty-write.yaml#steps[13].A A SELECT id, price FROM items ORDER BY id M18 MySQL 8.4.11, InnoDB; before step: A=READ UNCOMMITTED, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ UNCOMMITTED, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01626 current scenarios/mysql/02-isolation/dirty-write.yaml:42 scenarios/mysql/02-isolation/dirty-write.yaml#steps[13].expect[0].id id 1 M18 MySQL 8.4.11, InnoDB; before step: A=READ UNCOMMITTED, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ UNCOMMITTED, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01627 current scenarios/mysql/02-isolation/dirty-write.yaml:42 scenarios/mysql/02-isolation/dirty-write.yaml#steps[13].expect[0].price price 12 M18 MySQL 8.4.11, InnoDB; before step: A=READ UNCOMMITTED, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ UNCOMMITTED, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01628 current scenarios/mysql/02-isolation/dirty-write.yaml:42 scenarios/mysql/02-isolation/dirty-write.yaml#steps[13].expect[1].id id 2 M18 MySQL 8.4.11, InnoDB; before step: A=READ UNCOMMITTED, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ UNCOMMITTED, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01629 current scenarios/mysql/02-isolation/dirty-write.yaml:42 scenarios/mysql/02-isolation/dirty-write.yaml#steps[13].expect[1].price price 22 M18 MySQL 8.4.11, InnoDB; before step: A=READ UNCOMMITTED, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ UNCOMMITTED, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01630 current scenarios/mysql/02-isolation/dirty-write.yaml:43 scenarios/mysql/02-isolation/dirty-write.yaml#steps[13].comment comment both of B's prices in this schedule M18 MySQL 8.4.11, InnoDB; before step: A=READ UNCOMMITTED, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ UNCOMMITTED, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01631 current scenarios/mysql/02-isolation/dirty-write.yaml:44 scenarios/mysql/02-isolation/dirty-write.yaml#steps[13].tl tl SELECT → 12, 22 (both B) M18 MySQL 8.4.11, InnoDB; before step: A=READ UNCOMMITTED, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ UNCOMMITTED, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01632 current scenarios/mysql/02-isolation/intermediate-read.yaml:1 scenarios/mysql/02-isolation/intermediate-read.yaml#title title READ UNCOMMITTED serves drafts absent from committed history M19 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01633 current scenarios/mysql/02-isolation/intermediate-read.yaml:2 scenarios/mysql/02-isolation/intermediate-read.yaml#claim claim "At READ UNCOMMITTED a reader can observe an intermediate value the writer later overwrites before committing (Adya's G1b, ""intermediate read""); a number absent from committed history. In the repeated READ COMMITTED schedule, B reads 110 while A's draft 555 is uncommitted." M19 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01634 current scenarios/mysql/02-isolation/intermediate-read.yaml:7 scenarios/mysql/02-isolation/intermediate-read.yaml#anomaly anomaly G1b M19 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01635 current scenarios/mysql/02-isolation/intermediate-read.yaml:8 scenarios/mysql/02-isolation/intermediate-read.yaml#setup setup "CREATE TABLE accounts (id int PRIMARY KEY, owner varchar(20) NOT NULL, balance int NOT NULL) ENGINE=InnoDB; INSERT INTO accounts VALUES (1, 'alice', 100); " M19 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01636 current scenarios/mysql/02-isolation/intermediate-read.yaml:11 scenarios/mysql/02-isolation/intermediate-read.yaml#sessions[0] sessions[0] A M19 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01637 current scenarios/mysql/02-isolation/intermediate-read.yaml:11 scenarios/mysql/02-isolation/intermediate-read.yaml#sessions[1] sessions[1] B M19 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01638 current scenarios/mysql/02-isolation/intermediate-read.yaml:13 scenarios/mysql/02-isolation/intermediate-read.yaml#steps[0].note note A recalculates alice's balance in two steps. B watches at READ UNCOMMITTED. M19 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01639 current scenarios/mysql/02-isolation/intermediate-read.yaml:14 scenarios/mysql/02-isolation/intermediate-read.yaml#steps[1].B B SET SESSION TRANSACTION ISOLATION LEVEL READ UNCOMMITTED M19 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01640 current scenarios/mysql/02-isolation/intermediate-read.yaml:15 scenarios/mysql/02-isolation/intermediate-read.yaml#steps[2].B B BEGIN M19 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01641 current scenarios/mysql/02-isolation/intermediate-read.yaml:17 scenarios/mysql/02-isolation/intermediate-read.yaml#steps[3].A A BEGIN M19 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01642 current scenarios/mysql/02-isolation/intermediate-read.yaml:18 scenarios/mysql/02-isolation/intermediate-read.yaml#steps[4].A A UPDATE accounts SET balance = 999 WHERE id = 1 M19 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01643 current scenarios/mysql/02-isolation/intermediate-read.yaml:19 scenarios/mysql/02-isolation/intermediate-read.yaml#steps[4].comment comment a working draft; A isn't done yet M19 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01644 current scenarios/mysql/02-isolation/intermediate-read.yaml:20 scenarios/mysql/02-isolation/intermediate-read.yaml#steps[4].tl tl UPDATE balance = 999 (a draft) M19 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01645 current scenarios/mysql/02-isolation/intermediate-read.yaml:22 scenarios/mysql/02-isolation/intermediate-read.yaml#steps[5].B B SELECT balance FROM accounts WHERE id = 1 M19 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01646 current scenarios/mysql/02-isolation/intermediate-read.yaml:23 scenarios/mysql/02-isolation/intermediate-read.yaml#steps[5].expect[0].balance balance 999 M19 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01647 current scenarios/mysql/02-isolation/intermediate-read.yaml:24 scenarios/mysql/02-isolation/intermediate-read.yaml#steps[5].comment comment B just read a draft M19 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01648 current scenarios/mysql/02-isolation/intermediate-read.yaml:25 scenarios/mysql/02-isolation/intermediate-read.yaml#steps[5].tl tl SELECT balance → 999 (reads the draft) M19 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01649 current scenarios/mysql/02-isolation/intermediate-read.yaml:27 scenarios/mysql/02-isolation/intermediate-read.yaml#steps[6].A A UPDATE accounts SET balance = 110 WHERE id = 1 M19 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01650 current scenarios/mysql/02-isolation/intermediate-read.yaml:28 scenarios/mysql/02-isolation/intermediate-read.yaml#steps[6].comment comment A settles on the final value… M19 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01651 current scenarios/mysql/02-isolation/intermediate-read.yaml:29 scenarios/mysql/02-isolation/intermediate-read.yaml#steps[6].tl tl UPDATE balance = 110 (final value) M19 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01652 current scenarios/mysql/02-isolation/intermediate-read.yaml:30 scenarios/mysql/02-isolation/intermediate-read.yaml#steps[7].A A COMMIT M19 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01653 current scenarios/mysql/02-isolation/intermediate-read.yaml:31 scenarios/mysql/02-isolation/intermediate-read.yaml#steps[7].tl tl COMMIT M19 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01654 current scenarios/mysql/02-isolation/intermediate-read.yaml:33 scenarios/mysql/02-isolation/intermediate-read.yaml#steps[8].B B SELECT balance FROM accounts WHERE id = 1 M19 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01655 current scenarios/mysql/02-isolation/intermediate-read.yaml:34 scenarios/mysql/02-isolation/intermediate-read.yaml#steps[8].expect[0].balance balance 110 M19 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01656 current scenarios/mysql/02-isolation/intermediate-read.yaml:35 scenarios/mysql/02-isolation/intermediate-read.yaml#steps[8].tl tl SELECT balance → 110 (999 never committed) M19 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01657 current scenarios/mysql/02-isolation/intermediate-read.yaml:36 scenarios/mysql/02-isolation/intermediate-read.yaml#steps[9].B B COMMIT M19 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01658 current scenarios/mysql/02-isolation/intermediate-read.yaml:38 scenarios/mysql/02-isolation/intermediate-read.yaml#steps[10].note note The committed history is 100 → 110. B read 999 without executing any application action. At READ COMMITTED, B now excludes A's draft 555: M19 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01659 current scenarios/mysql/02-isolation/intermediate-read.yaml:41 scenarios/mysql/02-isolation/intermediate-read.yaml#steps[11].B B SET SESSION TRANSACTION ISOLATION LEVEL READ COMMITTED M19 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=READ UNCOMMITTED, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=READ COMMITTED, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01660 current scenarios/mysql/02-isolation/intermediate-read.yaml:42 scenarios/mysql/02-isolation/intermediate-read.yaml#steps[12].B B BEGIN M19 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=READ COMMITTED, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01661 current scenarios/mysql/02-isolation/intermediate-read.yaml:43 scenarios/mysql/02-isolation/intermediate-read.yaml#steps[13].A A BEGIN M19 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01662 current scenarios/mysql/02-isolation/intermediate-read.yaml:44 scenarios/mysql/02-isolation/intermediate-read.yaml#steps[14].A A UPDATE accounts SET balance = 555 WHERE id = 1 M19 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01663 current scenarios/mysql/02-isolation/intermediate-read.yaml:45 scenarios/mysql/02-isolation/intermediate-read.yaml#steps[15].B B SELECT balance FROM accounts WHERE id = 1 M19 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01664 current scenarios/mysql/02-isolation/intermediate-read.yaml:46 scenarios/mysql/02-isolation/intermediate-read.yaml#steps[15].expect[0].balance balance 110 M19 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01665 current scenarios/mysql/02-isolation/intermediate-read.yaml:47 scenarios/mysql/02-isolation/intermediate-read.yaml#steps[15].comment comment no drafts served here M19 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01666 current scenarios/mysql/02-isolation/intermediate-read.yaml:48 scenarios/mysql/02-isolation/intermediate-read.yaml#steps[16].A A ROLLBACK M19 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01667 current scenarios/mysql/02-isolation/intermediate-read.yaml:49 scenarios/mysql/02-isolation/intermediate-read.yaml#steps[17].B B COMMIT M19 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=READ COMMITTED, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01668 current scenarios/mysql/02-isolation/lost-update-read-committed.yaml:1 scenarios/mysql/02-isolation/lost-update-read-committed.yaml#title title Lost update at READ COMMITTED M20 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01669 current scenarios/mysql/02-isolation/lost-update-read-committed.yaml:2 scenarios/mysql/02-isolation/lost-update-read-committed.yaml#claim claim Two read-modify-write transactions at READ COMMITTED can silently overwrite each other: two deposits of 10 grow the balance by only 10. M20 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01670 current scenarios/mysql/02-isolation/lost-update-read-committed.yaml:5 scenarios/mysql/02-isolation/lost-update-read-committed.yaml#anomaly anomaly P4 M20 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01671 current scenarios/mysql/02-isolation/lost-update-read-committed.yaml:6 scenarios/mysql/02-isolation/lost-update-read-committed.yaml#isolation isolation READ COMMITTED M20 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01672 current scenarios/mysql/02-isolation/lost-update-read-committed.yaml:7 scenarios/mysql/02-isolation/lost-update-read-committed.yaml#setup setup "CREATE TABLE accounts (id int PRIMARY KEY, owner varchar(20) NOT NULL, balance int NOT NULL) ENGINE=InnoDB; INSERT INTO accounts VALUES (1, 'alice', 100); " M20 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01673 current scenarios/mysql/02-isolation/lost-update-read-committed.yaml:10 scenarios/mysql/02-isolation/lost-update-read-committed.yaml#sessions[0] sessions[0] A M20 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01674 current scenarios/mysql/02-isolation/lost-update-read-committed.yaml:10 scenarios/mysql/02-isolation/lost-update-read-committed.yaml#sessions[1] sessions[1] B M20 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01675 current scenarios/mysql/02-isolation/lost-update-read-committed.yaml:12 scenarios/mysql/02-isolation/lost-update-read-committed.yaml#steps[0].note note Two app servers process a +10 deposit each: read the balance, add 10 in code, write it back. M20 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01676 current scenarios/mysql/02-isolation/lost-update-read-committed.yaml:15 scenarios/mysql/02-isolation/lost-update-read-committed.yaml#steps[1].A A SET TRANSACTION ISOLATION LEVEL READ COMMITTED M20 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01677 current scenarios/mysql/02-isolation/lost-update-read-committed.yaml:16 scenarios/mysql/02-isolation/lost-update-read-committed.yaml#steps[2].A A BEGIN M20 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01678 current scenarios/mysql/02-isolation/lost-update-read-committed.yaml:17 scenarios/mysql/02-isolation/lost-update-read-committed.yaml#steps[3].A A SELECT balance FROM accounts WHERE id = 1 M20 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01679 current scenarios/mysql/02-isolation/lost-update-read-committed.yaml:18 scenarios/mysql/02-isolation/lost-update-read-committed.yaml#steps[3].expect[0].balance balance 100 M20 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01680 current scenarios/mysql/02-isolation/lost-update-read-committed.yaml:19 scenarios/mysql/02-isolation/lost-update-read-committed.yaml#steps[3].capture capture readA M20 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01681 current scenarios/mysql/02-isolation/lost-update-read-committed.yaml:20 scenarios/mysql/02-isolation/lost-update-read-committed.yaml#steps[3].tl tl SELECT balance → 100 M20 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01682 current scenarios/mysql/02-isolation/lost-update-read-committed.yaml:22 scenarios/mysql/02-isolation/lost-update-read-committed.yaml#steps[4].B B SET TRANSACTION ISOLATION LEVEL READ COMMITTED M20 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, open transaction, autocommit=1; B=READ COMMITTED, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01683 current scenarios/mysql/02-isolation/lost-update-read-committed.yaml:23 scenarios/mysql/02-isolation/lost-update-read-committed.yaml#steps[5].B B BEGIN M20 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, open transaction, autocommit=1; B=READ COMMITTED, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, open transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01684 current scenarios/mysql/02-isolation/lost-update-read-committed.yaml:24 scenarios/mysql/02-isolation/lost-update-read-committed.yaml#steps[6].B B SELECT balance FROM accounts WHERE id = 1 M20 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, open transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, open transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01685 current scenarios/mysql/02-isolation/lost-update-read-committed.yaml:25 scenarios/mysql/02-isolation/lost-update-read-committed.yaml#steps[6].expect[0].balance balance 100 M20 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, open transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, open transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01686 current scenarios/mysql/02-isolation/lost-update-read-committed.yaml:26 scenarios/mysql/02-isolation/lost-update-read-committed.yaml#steps[6].capture capture readB M20 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, open transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, open transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01687 current scenarios/mysql/02-isolation/lost-update-read-committed.yaml:27 scenarios/mysql/02-isolation/lost-update-read-committed.yaml#steps[6].comment comment B reads the same 100; A hasn't committed M20 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, open transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, open transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01688 current scenarios/mysql/02-isolation/lost-update-read-committed.yaml:28 scenarios/mysql/02-isolation/lost-update-read-committed.yaml#steps[6].tl tl SELECT balance → 100 (same stale read) M20 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, open transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, open transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01689 current scenarios/mysql/02-isolation/lost-update-read-committed.yaml:30 scenarios/mysql/02-isolation/lost-update-read-committed.yaml#steps[7].A A UPDATE accounts SET balance = ${readA.balance} + 10 WHERE id = 1 M20 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, open transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, open transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01690 current scenarios/mysql/02-isolation/lost-update-read-committed.yaml:31 scenarios/mysql/02-isolation/lost-update-read-committed.yaml#steps[7].tl tl UPDATE balance = 100 + 10 M20 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, open transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, open transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01691 current scenarios/mysql/02-isolation/lost-update-read-committed.yaml:32 scenarios/mysql/02-isolation/lost-update-read-committed.yaml#steps[8].A A COMMIT M20 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, open transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01692 current scenarios/mysql/02-isolation/lost-update-read-committed.yaml:33 scenarios/mysql/02-isolation/lost-update-read-committed.yaml#steps[8].tl tl COMMIT M20 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, open transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01693 current scenarios/mysql/02-isolation/lost-update-read-committed.yaml:35 scenarios/mysql/02-isolation/lost-update-read-committed.yaml#steps[9].note note B uses its captured 100 plus 10 in this SQL UPDATE. A has committed; this stale replacement succeeds in the displayed schedule. M20 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01694 current scenarios/mysql/02-isolation/lost-update-read-committed.yaml:36 scenarios/mysql/02-isolation/lost-update-read-committed.yaml#steps[10].B B UPDATE accounts SET balance = ${readB.balance} + 10 WHERE id = 1 M20 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01695 current scenarios/mysql/02-isolation/lost-update-read-committed.yaml:37 scenarios/mysql/02-isolation/lost-update-read-committed.yaml#steps[10].tl tl UPDATE balance = 100 + 10 (stale math) M20 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01696 current scenarios/mysql/02-isolation/lost-update-read-committed.yaml:38 scenarios/mysql/02-isolation/lost-update-read-committed.yaml#steps[11].B B COMMIT M20 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01697 current scenarios/mysql/02-isolation/lost-update-read-committed.yaml:39 scenarios/mysql/02-isolation/lost-update-read-committed.yaml#steps[11].tl tl COMMIT M20 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01698 current scenarios/mysql/02-isolation/lost-update-read-committed.yaml:41 scenarios/mysql/02-isolation/lost-update-read-committed.yaml#steps[12].A A SELECT balance FROM accounts WHERE id = 1 M20 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01699 current scenarios/mysql/02-isolation/lost-update-read-committed.yaml:42 scenarios/mysql/02-isolation/lost-update-read-committed.yaml#steps[12].expect[0].balance balance 110 M20 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01700 current scenarios/mysql/02-isolation/lost-update-read-committed.yaml:43 scenarios/mysql/02-isolation/lost-update-read-committed.yaml#steps[12].comment comment two +10 deposits, but only one survived M20 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01701 current scenarios/mysql/02-isolation/lost-update-read-committed.yaml:44 scenarios/mysql/02-isolation/lost-update-read-committed.yaml#steps[12].tl tl SELECT balance → 110; one deposit gone M20 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01702 current scenarios/mysql/02-isolation/lost-update-read-committed.yaml:46 scenarios/mysql/02-isolation/lost-update-read-committed.yaml#steps[13].note note A's deposit vanished without any error. Fixes: atomic UPDATE or SELECT FOR UPDATE; see the lesson. M20 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01703 current scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml:1 scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml#title title REPEATABLE READ does NOT stop lost updates M21 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01704 current scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml:2 scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml#claim claim In this InnoDB REPEATABLE READ schedule, both transactions read 100 and commit writes of that value plus 10 without error; the final balance is 110, not 120. A stale literal write is not rejected merely for staleness. M21 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01705 current scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml:6 scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml#anomaly anomaly P4 M21 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01706 current scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml:7 scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml#isolation isolation REPEATABLE READ M21 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01707 current scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml:8 scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml#setup setup "CREATE TABLE accounts (id int PRIMARY KEY, owner varchar(20) NOT NULL, balance int NOT NULL) ENGINE=InnoDB; INSERT INTO accounts VALUES (1, 'alice', 100); " M21 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01708 current scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml:11 scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml#sessions[0] sessions[0] A M21 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01709 current scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml:11 scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml#sessions[1] sessions[1] B M21 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01710 current scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml:13 scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml#steps[0].note note The same two +10 deposits; this time at REPEATABLE READ, MySQL's default. M21 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01711 current scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml:14 scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml#steps[1].A A SET TRANSACTION ISOLATION LEVEL REPEATABLE READ M21 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01712 current scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml:15 scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml#steps[2].B B SET TRANSACTION ISOLATION LEVEL REPEATABLE READ M21 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01713 current scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml:16 scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml#steps[3].A A BEGIN M21 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01714 current scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml:17 scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml#steps[4].A A SELECT balance FROM accounts WHERE id = 1 M21 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01715 current scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml:18 scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml#steps[4].expect[0].balance balance 100 M21 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01716 current scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml:19 scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml#steps[4].capture capture readA M21 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01717 current scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml:20 scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml#steps[4].tl tl SELECT balance → 100 M21 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01718 current scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml:22 scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml#steps[5].B B BEGIN M21 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01719 current scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml:23 scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml#steps[6].B B SELECT balance FROM accounts WHERE id = 1 M21 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01720 current scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml:24 scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml#steps[6].expect[0].balance balance 100 M21 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01721 current scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml:25 scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml#steps[6].capture capture readB M21 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01722 current scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml:26 scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml#steps[6].tl tl SELECT balance → 100 (same snapshot) M21 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01723 current scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml:28 scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml#steps[7].A A UPDATE accounts SET balance = ${readA.balance} + 10 WHERE id = 1 M21 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01724 current scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml:29 scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml#steps[7].tl tl UPDATE balance = 100 + 10 M21 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01725 current scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml:30 scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml#steps[8].A A COMMIT M21 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01726 current scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml:31 scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml#steps[8].tl tl COMMIT M21 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01727 current scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml:33 scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml#steps[9].note note B's snapshot predates A's commit; but MySQL's UPDATE acts on the CURRENT row and raises nothing. M21 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01728 current scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml:34 scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml#steps[10].B B UPDATE accounts SET balance = ${readB.balance} + 10 WHERE id = 1 M21 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01729 current scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml:35 scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml#steps[10].tl tl UPDATE balance = 100 + 10; no error! M21 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01730 current scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml:36 scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml#steps[11].B B COMMIT M21 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01731 current scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml:37 scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml#steps[11].tl tl COMMIT M21 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01732 current scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml:39 scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml#steps[12].A A SELECT balance FROM accounts WHERE id = 1 M21 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01733 current scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml:40 scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml#steps[12].expect[0].balance balance 110 M21 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01734 current scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml:41 scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml#steps[12].comment comment A's deposit is gone; silently, even at REPEATABLE READ M21 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01735 current scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml:42 scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml#steps[12].tl tl SELECT balance → 110; deposit gone, silently M21 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01736 current scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml:44 scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml#steps[13].note note PostgreSQL refuses B's write here (SQLSTATE 40001). MySQL does not; don't port that assumption. M21 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01737 current scenarios/mysql/02-isolation/non-repeatable-read.yaml:1 scenarios/mysql/02-isolation/non-repeatable-read.yaml#title title Non-repeatable read under READ COMMITTED M22 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01738 current scenarios/mysql/02-isolation/non-repeatable-read.yaml:2 scenarios/mysql/02-isolation/non-repeatable-read.yaml#claim claim At READ COMMITTED, a transaction can read two different values for the same row; other transactions' commits become visible between its statements. M22 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01739 current scenarios/mysql/02-isolation/non-repeatable-read.yaml:5 scenarios/mysql/02-isolation/non-repeatable-read.yaml#anomaly anomaly P2 M22 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01740 current scenarios/mysql/02-isolation/non-repeatable-read.yaml:6 scenarios/mysql/02-isolation/non-repeatable-read.yaml#isolation isolation READ COMMITTED M22 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01741 current scenarios/mysql/02-isolation/non-repeatable-read.yaml:7 scenarios/mysql/02-isolation/non-repeatable-read.yaml#setup setup "CREATE TABLE accounts (id int PRIMARY KEY, owner varchar(20) NOT NULL, balance int NOT NULL) ENGINE=InnoDB; INSERT INTO accounts VALUES (1, 'alice', 100); " M22 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01742 current scenarios/mysql/02-isolation/non-repeatable-read.yaml:10 scenarios/mysql/02-isolation/non-repeatable-read.yaml#sessions[0] sessions[0] A M22 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01743 current scenarios/mysql/02-isolation/non-repeatable-read.yaml:10 scenarios/mysql/02-isolation/non-repeatable-read.yaml#sessions[1] sessions[1] B M22 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01744 current scenarios/mysql/02-isolation/non-repeatable-read.yaml:12 scenarios/mysql/02-isolation/non-repeatable-read.yaml#steps[0].A A SET TRANSACTION ISOLATION LEVEL READ COMMITTED M22 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01745 current scenarios/mysql/02-isolation/non-repeatable-read.yaml:13 scenarios/mysql/02-isolation/non-repeatable-read.yaml#steps[1].A A BEGIN M22 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01746 current scenarios/mysql/02-isolation/non-repeatable-read.yaml:14 scenarios/mysql/02-isolation/non-repeatable-read.yaml#steps[2].A A SELECT balance FROM accounts WHERE id = 1 M22 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01747 current scenarios/mysql/02-isolation/non-repeatable-read.yaml:15 scenarios/mysql/02-isolation/non-repeatable-read.yaml#steps[2].expect[0].balance balance 100 M22 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01748 current scenarios/mysql/02-isolation/non-repeatable-read.yaml:16 scenarios/mysql/02-isolation/non-repeatable-read.yaml#steps[2].tl tl SELECT balance → 100 M22 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01749 current scenarios/mysql/02-isolation/non-repeatable-read.yaml:18 scenarios/mysql/02-isolation/non-repeatable-read.yaml#steps[3].note note While A's transaction is still open, B updates the row and commits. M22 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01750 current scenarios/mysql/02-isolation/non-repeatable-read.yaml:19 scenarios/mysql/02-isolation/non-repeatable-read.yaml#steps[4].B B UPDATE accounts SET balance = 200 WHERE id = 1 M22 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01751 current scenarios/mysql/02-isolation/non-repeatable-read.yaml:20 scenarios/mysql/02-isolation/non-repeatable-read.yaml#steps[4].tl tl UPDATE balance = 200 (autocommit) M22 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01752 current scenarios/mysql/02-isolation/non-repeatable-read.yaml:22 scenarios/mysql/02-isolation/non-repeatable-read.yaml#steps[5].A A SELECT balance FROM accounts WHERE id = 1 M22 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01753 current scenarios/mysql/02-isolation/non-repeatable-read.yaml:23 scenarios/mysql/02-isolation/non-repeatable-read.yaml#steps[5].expect[0].balance balance 200 M22 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01754 current scenarios/mysql/02-isolation/non-repeatable-read.yaml:24 scenarios/mysql/02-isolation/non-repeatable-read.yaml#steps[5].comment comment same query, same transaction; different answer M22 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01755 current scenarios/mysql/02-isolation/non-repeatable-read.yaml:25 scenarios/mysql/02-isolation/non-repeatable-read.yaml#steps[5].tl tl SELECT balance → 200; same txn, different answer M22 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01756 current scenarios/mysql/02-isolation/non-repeatable-read.yaml:26 scenarios/mysql/02-isolation/non-repeatable-read.yaml#steps[6].A A COMMIT M22 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01757 current scenarios/mysql/02-isolation/non-repeatable-read.yaml:28 scenarios/mysql/02-isolation/non-repeatable-read.yaml#steps[7].note note These nonlocking SELECTs did not wait for row locks. The interleaving with UPDATEs makes B wait for A's row lock. M22 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01758 current scenarios/mysql/02-isolation/non-repeatable-read.yaml:31 scenarios/mysql/02-isolation/non-repeatable-read.yaml#steps[8].A A BEGIN M22 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01759 current scenarios/mysql/02-isolation/non-repeatable-read.yaml:32 scenarios/mysql/02-isolation/non-repeatable-read.yaml#steps[9].A A UPDATE accounts SET balance = 300 WHERE id = 1 M22 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01760 current scenarios/mysql/02-isolation/non-repeatable-read.yaml:34 scenarios/mysql/02-isolation/non-repeatable-read.yaml#steps[10].B B UPDATE accounts SET balance = 400 WHERE id = 1 M22 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01761 current scenarios/mysql/02-isolation/non-repeatable-read.yaml:35 scenarios/mysql/02-isolation/non-repeatable-read.yaml#steps[10].blocks blocks p1 M22 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01762 current scenarios/mysql/02-isolation/non-repeatable-read.yaml:37 scenarios/mysql/02-isolation/non-repeatable-read.yaml#steps[11].A A COMMIT M22 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01763 current scenarios/mysql/02-isolation/non-repeatable-read.yaml:38 scenarios/mysql/02-isolation/non-repeatable-read.yaml#steps[11].comment comment releases the row lock M22 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01764 current scenarios/mysql/02-isolation/non-repeatable-read.yaml:39 scenarios/mysql/02-isolation/non-repeatable-read.yaml#steps[12].success success p1 M22 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01765 current scenarios/mysql/02-isolation/non-repeatable-read.yaml:40 scenarios/mysql/02-isolation/non-repeatable-read.yaml#steps[12].affected affected 1 M22 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01766 current scenarios/mysql/02-isolation/non-repeatable-read.yaml:42 scenarios/mysql/02-isolation/non-repeatable-read.yaml#steps[13].B B SELECT balance FROM accounts WHERE id = 1 M22 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01767 current scenarios/mysql/02-isolation/non-repeatable-read.yaml:43 scenarios/mysql/02-isolation/non-repeatable-read.yaml#steps[13].expect[0].balance balance 400 M22 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01768 current scenarios/mysql/02-isolation/non-repeatable-read.yaml:44 scenarios/mysql/02-isolation/non-repeatable-read.yaml#steps[13].comment comment B's write landed on top of A's committed 300 M22 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01769 current scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:1 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#title title A committed transaction can half-vanish at READ UNCOMMITTED M23 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01770 current scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:2 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#claim claim "At READ UNCOMMITTED a reader can see a later transaction's uncommitted overwrite of one row while relying on the overwritten transaction's other row (Adya's OTV, ""observed transaction vanishes""); the committed transaction is visible only in pieces in this schedule. The repeated READ COMMITTED SELECTs exclude A's draft and see both rows after commit; separate statements do not have one shared snapshot." M23 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01771 current scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:9 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#anomaly anomaly OTV M23 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01772 current scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:10 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#setup setup "CREATE TABLE accounts (id int PRIMARY KEY, owner varchar(20) NOT NULL, balance int NOT NULL) ENGINE=InnoDB; INSERT INTO accounts VALUES (1, 'alice', 100), (2, 'bob', 100); " M23 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01773 current scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:13 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#sessions[0] sessions[0] A M23 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01774 current scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:13 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#sessions[1] sessions[1] B M23 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01775 current scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:13 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#sessions[2] sessions[2] C M23 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01776 current scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:15 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[0].note note A rewrites both balances and commits. B overwrites one of them. C reads at READ UNCOMMITTED. M23 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01777 current scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:16 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[1].C C SET SESSION TRANSACTION ISOLATION LEVEL READ UNCOMMITTED M23 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ UNCOMMITTED, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01778 current scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:17 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[2].C C BEGIN M23 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ UNCOMMITTED, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ UNCOMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01779 current scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:19 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[3].A A BEGIN M23 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ UNCOMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01780 current scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:20 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[4].A A UPDATE accounts SET balance = 11 WHERE id = 1 M23 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ UNCOMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01781 current scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:21 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[4].tl tl id1 = 11 M23 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ UNCOMMITTED, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01782 current scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:22 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[5].A A UPDATE accounts SET balance = 19 WHERE id = 2 M23 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ UNCOMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01783 current scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:23 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[5].tl tl id2 = 19 M23 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ UNCOMMITTED, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01784 current scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:25 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[6].B B BEGIN M23 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; C=READ UNCOMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01785 current scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:26 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[7].B B UPDATE accounts SET balance = 12 WHERE id = 1 M23 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; C=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; C=READ UNCOMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01786 current scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:27 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[7].blocks blocks p1 M23 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; C=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; C=READ UNCOMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01787 current scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:28 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[7].tl tl UPDATE id1 = 12 M23 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; C=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; C=READ UNCOMMITTED, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01788 current scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:29 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[8].A A COMMIT M23 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; C=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; C=READ UNCOMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01789 current scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:30 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[8].comment comment A is committed; its writes are 11 and 19 M23 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; C=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; C=READ UNCOMMITTED, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01790 current scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:31 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[8].tl tl COMMIT (11 and 19) M23 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; C=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; C=READ UNCOMMITTED, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01791 current scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:32 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[9].success success p1 M23 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; C=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; C=READ UNCOMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01792 current scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:34 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[10].C C SELECT id, balance FROM accounts ORDER BY id M23 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; C=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; C=READ UNCOMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01793 current scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:35 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[10].expect[0].id id 1 M23 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; C=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; C=READ UNCOMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01794 current scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:35 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[10].expect[0].balance balance 12 M23 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; C=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; C=READ UNCOMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01795 current scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:35 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[10].expect[1].id id 2 M23 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; C=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; C=READ UNCOMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01796 current scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:35 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[10].expect[1].balance balance 19 M23 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; C=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; C=READ UNCOMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01797 current scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:36 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[10].comment comment 12 is B's uncommitted draft, 19 is A's commit; A's 11 already vanished M23 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; C=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; C=READ UNCOMMITTED, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01798 current scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:37 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[10].tl tl C reads → 12, 19 (A's 11 already gone) M23 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; C=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; C=READ UNCOMMITTED, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01799 current scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:39 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[11].note note C never saw the committed state {11, 19}. Half of A was overwritten before C observed it. C's returned rows combine B's draft with A's committed second row. B now finishes: M23 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; C=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; C=READ UNCOMMITTED, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01800 current scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:43 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[12].B B UPDATE accounts SET balance = 18 WHERE id = 2 M23 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; C=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; C=READ UNCOMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01801 current scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:44 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[13].B B COMMIT M23 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; C=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ UNCOMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01802 current scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:45 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[14].C C SELECT id, balance FROM accounts ORDER BY id M23 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ UNCOMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01803 current scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:46 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[14].expect[0].id id 1 M23 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ UNCOMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01804 current scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:46 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[14].expect[0].balance balance 12 M23 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ UNCOMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01805 current scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:46 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[14].expect[1].id id 2 M23 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ UNCOMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01806 current scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:46 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[14].expect[1].balance balance 18 M23 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ UNCOMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01807 current scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:47 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[15].C C COMMIT M23 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ UNCOMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ UNCOMMITTED, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01808 current scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:49 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[16].note note These READ COMMITTED SELECTs exclude A's uncommitted changes, then include its commit: M23 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ UNCOMMITTED, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ UNCOMMITTED, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01809 current scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:50 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[17].C C SET SESSION TRANSACTION ISOLATION LEVEL READ COMMITTED M23 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ UNCOMMITTED, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ COMMITTED, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01810 current scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:51 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[18].C C BEGIN M23 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ COMMITTED, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ COMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01811 current scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:52 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[19].A A BEGIN M23 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ COMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ COMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01812 current scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:53 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[20].A A UPDATE accounts SET balance = 51 WHERE id = 1 M23 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ COMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ COMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01813 current scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:54 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[21].A A UPDATE accounts SET balance = 59 WHERE id = 2 M23 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ COMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ COMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01814 current scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:55 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[22].C C SELECT id, balance FROM accounts ORDER BY id M23 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ COMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ COMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01815 current scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:56 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[22].expect[0].id id 1 M23 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ COMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ COMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01816 current scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:56 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[22].expect[0].balance balance 12 M23 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ COMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ COMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01817 current scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:56 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[22].expect[1].id id 2 M23 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ COMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ COMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01818 current scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:56 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[22].expect[1].balance balance 18 M23 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ COMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ COMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01819 current scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:57 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[22].comment comment all of the last committed state; nothing of A's draft M23 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ COMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ COMMITTED, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01820 current scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:58 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[23].A A COMMIT M23 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ COMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ COMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01821 current scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:59 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[24].C C SELECT id, balance FROM accounts ORDER BY id M23 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ COMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ COMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01822 current scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:60 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[24].expect[0].id id 1 M23 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ COMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ COMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01823 current scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:60 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[24].expect[0].balance balance 51 M23 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ COMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ COMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01824 current scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:60 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[24].expect[1].id id 2 M23 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ COMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ COMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01825 current scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:60 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[24].expect[1].balance balance 59 M23 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ COMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ COMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01826 current scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:61 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[24].comment comment and now all of A, atomically M23 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ COMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ COMMITTED, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01827 current scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml:62 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#steps[25].C C COMMIT M23 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ COMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; C=READ COMMITTED, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01828 current scenarios/mysql/02-isolation/phantom-read.yaml:1 scenarios/mysql/02-isolation/phantom-read.yaml#title title Phantom read under READ COMMITTED M24 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01829 current scenarios/mysql/02-isolation/phantom-read.yaml:2 scenarios/mysql/02-isolation/phantom-read.yaml#claim claim At READ COMMITTED, re-running the same range query inside one transaction can return rows that weren't there before; phantoms. M24 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01830 current scenarios/mysql/02-isolation/phantom-read.yaml:5 scenarios/mysql/02-isolation/phantom-read.yaml#anomaly anomaly PMP M24 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01831 current scenarios/mysql/02-isolation/phantom-read.yaml:6 scenarios/mysql/02-isolation/phantom-read.yaml#isolation isolation READ COMMITTED M24 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01832 current scenarios/mysql/02-isolation/phantom-read.yaml:7 scenarios/mysql/02-isolation/phantom-read.yaml#setup setup "CREATE TABLE orders (id int PRIMARY KEY, amount int NOT NULL) ENGINE=InnoDB; INSERT INTO orders VALUES (1, 500), (2, 300); " M24 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01833 current scenarios/mysql/02-isolation/phantom-read.yaml:10 scenarios/mysql/02-isolation/phantom-read.yaml#sessions[0] sessions[0] A M24 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01834 current scenarios/mysql/02-isolation/phantom-read.yaml:10 scenarios/mysql/02-isolation/phantom-read.yaml#sessions[1] sessions[1] B M24 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01835 current scenarios/mysql/02-isolation/phantom-read.yaml:12 scenarios/mysql/02-isolation/phantom-read.yaml#steps[0].note note A runs two SELECTs inside one transaction: a count first, then a count and total. M24 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01836 current scenarios/mysql/02-isolation/phantom-read.yaml:15 scenarios/mysql/02-isolation/phantom-read.yaml#steps[1].A A SET TRANSACTION ISOLATION LEVEL READ COMMITTED M24 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01837 current scenarios/mysql/02-isolation/phantom-read.yaml:16 scenarios/mysql/02-isolation/phantom-read.yaml#steps[2].A A BEGIN M24 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01838 current scenarios/mysql/02-isolation/phantom-read.yaml:18 scenarios/mysql/02-isolation/phantom-read.yaml#steps[3].A A SELECT count(*) AS n FROM orders WHERE amount >= 100 M24 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01839 current scenarios/mysql/02-isolation/phantom-read.yaml:19 scenarios/mysql/02-isolation/phantom-read.yaml#steps[3].expect[0].n n 2 M24 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01840 current scenarios/mysql/02-isolation/phantom-read.yaml:20 scenarios/mysql/02-isolation/phantom-read.yaml#steps[3].tl tl count(amount ≥ 100) → 2 M24 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01841 current scenarios/mysql/02-isolation/phantom-read.yaml:22 scenarios/mysql/02-isolation/phantom-read.yaml#steps[4].note note Between A's two statements, B commits a new order that matches A's WHERE clause. M24 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01842 current scenarios/mysql/02-isolation/phantom-read.yaml:23 scenarios/mysql/02-isolation/phantom-read.yaml#steps[5].B B INSERT INTO orders VALUES (3, 700) M24 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01843 current scenarios/mysql/02-isolation/phantom-read.yaml:24 scenarios/mysql/02-isolation/phantom-read.yaml#steps[5].tl tl INSERT order 3 (autocommit) M24 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01844 current scenarios/mysql/02-isolation/phantom-read.yaml:26 scenarios/mysql/02-isolation/phantom-read.yaml#steps[6].A A SELECT count(*) AS n, CAST(sum(amount) AS SIGNED) AS total FROM orders WHERE amount >= 100 M24 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01845 current scenarios/mysql/02-isolation/phantom-read.yaml:27 scenarios/mysql/02-isolation/phantom-read.yaml#steps[6].expect[0].n n 3 M24 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01846 current scenarios/mysql/02-isolation/phantom-read.yaml:27 scenarios/mysql/02-isolation/phantom-read.yaml#steps[6].expect[0].total total 1500 M24 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01847 current scenarios/mysql/02-isolation/phantom-read.yaml:28 scenarios/mysql/02-isolation/phantom-read.yaml#steps[6].comment comment a third row appeared out of nowhere; a phantom M24 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01848 current scenarios/mysql/02-isolation/phantom-read.yaml:29 scenarios/mysql/02-isolation/phantom-read.yaml#steps[6].tl tl recount → 3, total 1500; a phantom M24 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01849 current scenarios/mysql/02-isolation/phantom-read.yaml:31 scenarios/mysql/02-isolation/phantom-read.yaml#steps[7].A A COMMIT M24 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01850 current scenarios/mysql/02-isolation/phantom-read.yaml:32 scenarios/mysql/02-isolation/phantom-read.yaml#steps[8].note note A's first SELECT returns count 2; the later SELECT returns count 3 and total 1500. No report publication is executed. M24 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01851 current scenarios/mysql/02-isolation/read-skew.yaml:1 scenarios/mysql/02-isolation/read-skew.yaml#title title Read skew: one transaction, two rows, an impossible total M25 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01852 current scenarios/mysql/02-isolation/read-skew.yaml:2 scenarios/mysql/02-isolation/read-skew.yaml#claim claim "At READ COMMITTED, a transaction reading two rows around a concurrent transfer observes money that never existed (Adya's G-single, ""read skew""); the repeated REPEATABLE READ schedule returns 25 and 75 from one snapshot, with no writes by the reader." M25 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01853 current scenarios/mysql/02-isolation/read-skew.yaml:7 scenarios/mysql/02-isolation/read-skew.yaml#anomaly anomaly G-single M25 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01854 current scenarios/mysql/02-isolation/read-skew.yaml:8 scenarios/mysql/02-isolation/read-skew.yaml#setup setup "CREATE TABLE accounts (id int PRIMARY KEY, owner varchar(20) NOT NULL, balance int NOT NULL) ENGINE=InnoDB; INSERT INTO accounts VALUES (1, 'alice', 50), (2, 'bob', 50); " M25 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01855 current scenarios/mysql/02-isolation/read-skew.yaml:11 scenarios/mysql/02-isolation/read-skew.yaml#sessions[0] sessions[0] A M25 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01856 current scenarios/mysql/02-isolation/read-skew.yaml:11 scenarios/mysql/02-isolation/read-skew.yaml#sessions[1] sessions[1] B M25 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01857 current scenarios/mysql/02-isolation/read-skew.yaml:13 scenarios/mysql/02-isolation/read-skew.yaml#steps[0].note note The rule: alice + bob = 100 in each committed state. A models an auditor reading the accounts row by row; B transfers 25 between them mid-audit. M25 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01858 current scenarios/mysql/02-isolation/read-skew.yaml:16 scenarios/mysql/02-isolation/read-skew.yaml#steps[1].A A SET SESSION TRANSACTION ISOLATION LEVEL READ COMMITTED M25 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01859 current scenarios/mysql/02-isolation/read-skew.yaml:17 scenarios/mysql/02-isolation/read-skew.yaml#steps[2].A A BEGIN M25 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01860 current scenarios/mysql/02-isolation/read-skew.yaml:18 scenarios/mysql/02-isolation/read-skew.yaml#steps[3].A A SELECT balance FROM accounts WHERE owner = 'alice' M25 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01861 current scenarios/mysql/02-isolation/read-skew.yaml:19 scenarios/mysql/02-isolation/read-skew.yaml#steps[3].expect[0].balance balance 50 M25 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01862 current scenarios/mysql/02-isolation/read-skew.yaml:20 scenarios/mysql/02-isolation/read-skew.yaml#steps[3].tl tl read alice → 50 M25 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01863 current scenarios/mysql/02-isolation/read-skew.yaml:22 scenarios/mysql/02-isolation/read-skew.yaml#steps[4].B B BEGIN M25 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01864 current scenarios/mysql/02-isolation/read-skew.yaml:23 scenarios/mysql/02-isolation/read-skew.yaml#steps[5].B B UPDATE accounts SET balance = balance - 25 WHERE owner = 'alice' M25 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01865 current scenarios/mysql/02-isolation/read-skew.yaml:24 scenarios/mysql/02-isolation/read-skew.yaml#steps[5].tl tl alice −25 M25 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01866 current scenarios/mysql/02-isolation/read-skew.yaml:25 scenarios/mysql/02-isolation/read-skew.yaml#steps[6].B B UPDATE accounts SET balance = balance + 25 WHERE owner = 'bob' M25 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01867 current scenarios/mysql/02-isolation/read-skew.yaml:26 scenarios/mysql/02-isolation/read-skew.yaml#steps[6].tl tl bob +25 M25 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01868 current scenarios/mysql/02-isolation/read-skew.yaml:27 scenarios/mysql/02-isolation/read-skew.yaml#steps[7].B B COMMIT M25 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01869 current scenarios/mysql/02-isolation/read-skew.yaml:28 scenarios/mysql/02-isolation/read-skew.yaml#steps[7].comment comment a perfectly correct transfer; atomic, invariant preserved M25 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01870 current scenarios/mysql/02-isolation/read-skew.yaml:29 scenarios/mysql/02-isolation/read-skew.yaml#steps[7].tl tl COMMIT (transfer done) M25 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01871 current scenarios/mysql/02-isolation/read-skew.yaml:31 scenarios/mysql/02-isolation/read-skew.yaml#steps[8].A A SELECT balance FROM accounts WHERE owner = 'bob' M25 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01872 current scenarios/mysql/02-isolation/read-skew.yaml:32 scenarios/mysql/02-isolation/read-skew.yaml#steps[8].expect[0].balance balance 75 M25 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01873 current scenarios/mysql/02-isolation/read-skew.yaml:33 scenarios/mysql/02-isolation/read-skew.yaml#steps[8].comment comment 50 + 75 = 125. The auditor found 25 that never existed. M25 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01874 current scenarios/mysql/02-isolation/read-skew.yaml:34 scenarios/mysql/02-isolation/read-skew.yaml#steps[8].tl tl read bob → 75 (50 + 75 = 125!) M25 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01875 current scenarios/mysql/02-isolation/read-skew.yaml:35 scenarios/mysql/02-isolation/read-skew.yaml#steps[9].A A COMMIT M25 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01876 current scenarios/mysql/02-isolation/read-skew.yaml:37 scenarios/mysql/02-isolation/read-skew.yaml#steps[10].note note Neither row was ever wrong; A read alice BEFORE the transfer and bob AFTER it. The repeated REPEATABLE READ consistent SELECTs use one snapshot; the reader makes no changes of its own: M25 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=READ COMMITTED, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01877 current scenarios/mysql/02-isolation/read-skew.yaml:41 scenarios/mysql/02-isolation/read-skew.yaml#steps[11].A A SET SESSION TRANSACTION ISOLATION LEVEL REPEATABLE READ M25 MySQL 8.4.11, InnoDB; before step: A=READ COMMITTED, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01878 current scenarios/mysql/02-isolation/read-skew.yaml:42 scenarios/mysql/02-isolation/read-skew.yaml#steps[12].A A BEGIN M25 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01879 current scenarios/mysql/02-isolation/read-skew.yaml:43 scenarios/mysql/02-isolation/read-skew.yaml#steps[13].A A SELECT balance FROM accounts WHERE owner = 'alice' M25 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01880 current scenarios/mysql/02-isolation/read-skew.yaml:44 scenarios/mysql/02-isolation/read-skew.yaml#steps[13].expect[0].balance balance 25 M25 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01881 current scenarios/mysql/02-isolation/read-skew.yaml:46 scenarios/mysql/02-isolation/read-skew.yaml#steps[14].B B BEGIN M25 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01882 current scenarios/mysql/02-isolation/read-skew.yaml:47 scenarios/mysql/02-isolation/read-skew.yaml#steps[15].B B UPDATE accounts SET balance = balance - 10 WHERE owner = 'alice' M25 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01883 current scenarios/mysql/02-isolation/read-skew.yaml:48 scenarios/mysql/02-isolation/read-skew.yaml#steps[16].B B UPDATE accounts SET balance = balance + 10 WHERE owner = 'bob' M25 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01884 current scenarios/mysql/02-isolation/read-skew.yaml:49 scenarios/mysql/02-isolation/read-skew.yaml#steps[17].B B COMMIT M25 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01885 current scenarios/mysql/02-isolation/read-skew.yaml:51 scenarios/mysql/02-isolation/read-skew.yaml#steps[18].A A SELECT balance FROM accounts WHERE owner = 'bob' M25 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01886 current scenarios/mysql/02-isolation/read-skew.yaml:52 scenarios/mysql/02-isolation/read-skew.yaml#steps[18].expect[0].balance balance 75 M25 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01887 current scenarios/mysql/02-isolation/read-skew.yaml:53 scenarios/mysql/02-isolation/read-skew.yaml#steps[18].comment comment 25 + 75 = 100; one snapshot, one moment in time M25 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01888 current scenarios/mysql/02-isolation/read-skew.yaml:54 scenarios/mysql/02-isolation/read-skew.yaml#steps[19].A A COMMIT M25 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01889 current scenarios/mysql/02-isolation/stable-snapshot.yaml:1 scenarios/mysql/02-isolation/stable-snapshot.yaml#title title REPEATABLE READ: one snapshot for the whole transaction M26 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01890 current scenarios/mysql/02-isolation/stable-snapshot.yaml:2 scenarios/mysql/02-isolation/stable-snapshot.yaml#claim claim In this InnoDB REPEATABLE READ schedule, the first consistent SELECT includes a commit after BEGIN. Later consistent SELECTs exclude B's later UPDATE and INSERT, include A's own UPDATE, and refresh after A commits. M26 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01891 current scenarios/mysql/02-isolation/stable-snapshot.yaml:6 scenarios/mysql/02-isolation/stable-snapshot.yaml#anomaly anomaly P2 M26 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01892 current scenarios/mysql/02-isolation/stable-snapshot.yaml:7 scenarios/mysql/02-isolation/stable-snapshot.yaml#isolation isolation REPEATABLE READ M26 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01893 current scenarios/mysql/02-isolation/stable-snapshot.yaml:8 scenarios/mysql/02-isolation/stable-snapshot.yaml#setup setup "CREATE TABLE accounts (id int PRIMARY KEY, owner varchar(20) NOT NULL, balance int NOT NULL) ENGINE=InnoDB; INSERT INTO accounts VALUES (1, 'alice', 100), (2, 'bob', 50); " M26 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01894 current scenarios/mysql/02-isolation/stable-snapshot.yaml:11 scenarios/mysql/02-isolation/stable-snapshot.yaml#sessions[0] sessions[0] A M26 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01895 current scenarios/mysql/02-isolation/stable-snapshot.yaml:11 scenarios/mysql/02-isolation/stable-snapshot.yaml#sessions[1] sessions[1] B M26 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01896 current scenarios/mysql/02-isolation/stable-snapshot.yaml:13 scenarios/mysql/02-isolation/stable-snapshot.yaml#steps[0].A A SET TRANSACTION ISOLATION LEVEL REPEATABLE READ M26 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01897 current scenarios/mysql/02-isolation/stable-snapshot.yaml:14 scenarios/mysql/02-isolation/stable-snapshot.yaml#steps[1].A A BEGIN M26 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01898 current scenarios/mysql/02-isolation/stable-snapshot.yaml:15 scenarios/mysql/02-isolation/stable-snapshot.yaml#steps[2].B B UPDATE accounts SET balance = 120 WHERE id = 1 M26 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01899 current scenarios/mysql/02-isolation/stable-snapshot.yaml:17 scenarios/mysql/02-isolation/stable-snapshot.yaml#steps[3].note note The first consistent table read includes B's commit after BEGIN. M26 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01900 current scenarios/mysql/02-isolation/stable-snapshot.yaml:18 scenarios/mysql/02-isolation/stable-snapshot.yaml#steps[4].A A SELECT id, balance FROM accounts ORDER BY id M26 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01901 current scenarios/mysql/02-isolation/stable-snapshot.yaml:19 scenarios/mysql/02-isolation/stable-snapshot.yaml#steps[4].expect[0].id id 1 M26 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01902 current scenarios/mysql/02-isolation/stable-snapshot.yaml:19 scenarios/mysql/02-isolation/stable-snapshot.yaml#steps[4].expect[0].balance balance 120 M26 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01903 current scenarios/mysql/02-isolation/stable-snapshot.yaml:19 scenarios/mysql/02-isolation/stable-snapshot.yaml#steps[4].expect[1].id id 2 M26 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01904 current scenarios/mysql/02-isolation/stable-snapshot.yaml:19 scenarios/mysql/02-isolation/stable-snapshot.yaml#steps[4].expect[1].balance balance 50 M26 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01905 current scenarios/mysql/02-isolation/stable-snapshot.yaml:20 scenarios/mysql/02-isolation/stable-snapshot.yaml#steps[4].tl tl SELECT → 120, 50 (snapshot taken) M26 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01906 current scenarios/mysql/02-isolation/stable-snapshot.yaml:22 scenarios/mysql/02-isolation/stable-snapshot.yaml#steps[5].note note B changes an existing row AND inserts a new one; both committed instantly. M26 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01907 current scenarios/mysql/02-isolation/stable-snapshot.yaml:23 scenarios/mysql/02-isolation/stable-snapshot.yaml#steps[6].B B UPDATE accounts SET balance = 999 WHERE id = 1 M26 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01908 current scenarios/mysql/02-isolation/stable-snapshot.yaml:24 scenarios/mysql/02-isolation/stable-snapshot.yaml#steps[6].tl tl UPDATE id1 = 999 (committed) M26 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01909 current scenarios/mysql/02-isolation/stable-snapshot.yaml:25 scenarios/mysql/02-isolation/stable-snapshot.yaml#steps[7].B B INSERT INTO accounts VALUES (3, 'carol', 300) M26 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01910 current scenarios/mysql/02-isolation/stable-snapshot.yaml:26 scenarios/mysql/02-isolation/stable-snapshot.yaml#steps[7].tl tl INSERT carol (committed) M26 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01911 current scenarios/mysql/02-isolation/stable-snapshot.yaml:28 scenarios/mysql/02-isolation/stable-snapshot.yaml#steps[8].A A SELECT id, balance FROM accounts ORDER BY id M26 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01912 current scenarios/mysql/02-isolation/stable-snapshot.yaml:30 scenarios/mysql/02-isolation/stable-snapshot.yaml#steps[8].expect[0].id id 1 M26 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01913 current scenarios/mysql/02-isolation/stable-snapshot.yaml:30 scenarios/mysql/02-isolation/stable-snapshot.yaml#steps[8].expect[0].balance balance 120 M26 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01914 current scenarios/mysql/02-isolation/stable-snapshot.yaml:31 scenarios/mysql/02-isolation/stable-snapshot.yaml#steps[8].expect[1].id id 2 M26 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01915 current scenarios/mysql/02-isolation/stable-snapshot.yaml:31 scenarios/mysql/02-isolation/stable-snapshot.yaml#steps[8].expect[1].balance balance 50 M26 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01916 current scenarios/mysql/02-isolation/stable-snapshot.yaml:32 scenarios/mysql/02-isolation/stable-snapshot.yaml#steps[8].comment comment not 999; no non-repeatable read; and no carol; no phantom M26 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01917 current scenarios/mysql/02-isolation/stable-snapshot.yaml:33 scenarios/mysql/02-isolation/stable-snapshot.yaml#steps[8].tl tl SELECT → 120, 50; no 999, no carol M26 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01918 current scenarios/mysql/02-isolation/stable-snapshot.yaml:35 scenarios/mysql/02-isolation/stable-snapshot.yaml#steps[9].A A UPDATE accounts SET balance = balance + 10 WHERE id = 2 M26 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01919 current scenarios/mysql/02-isolation/stable-snapshot.yaml:36 scenarios/mysql/02-isolation/stable-snapshot.yaml#steps[10].A A SELECT id, balance FROM accounts ORDER BY id M26 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01920 current scenarios/mysql/02-isolation/stable-snapshot.yaml:37 scenarios/mysql/02-isolation/stable-snapshot.yaml#steps[10].expect[0].id id 1 M26 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01921 current scenarios/mysql/02-isolation/stable-snapshot.yaml:37 scenarios/mysql/02-isolation/stable-snapshot.yaml#steps[10].expect[0].balance balance 120 M26 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01922 current scenarios/mysql/02-isolation/stable-snapshot.yaml:37 scenarios/mysql/02-isolation/stable-snapshot.yaml#steps[10].expect[1].id id 2 M26 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01923 current scenarios/mysql/02-isolation/stable-snapshot.yaml:37 scenarios/mysql/02-isolation/stable-snapshot.yaml#steps[10].expect[1].balance balance 60 M26 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01924 current scenarios/mysql/02-isolation/stable-snapshot.yaml:38 scenarios/mysql/02-isolation/stable-snapshot.yaml#steps[10].comment comment own write is visible alongside the snapshot's old row 1 M26 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01925 current scenarios/mysql/02-isolation/stable-snapshot.yaml:40 scenarios/mysql/02-isolation/stable-snapshot.yaml#steps[11].A A COMMIT M26 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01926 current scenarios/mysql/02-isolation/stable-snapshot.yaml:41 scenarios/mysql/02-isolation/stable-snapshot.yaml#steps[11].tl tl COMMIT M26 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01927 current scenarios/mysql/02-isolation/stable-snapshot.yaml:43 scenarios/mysql/02-isolation/stable-snapshot.yaml#steps[12].note note After COMMIT, this standalone SELECT takes a fresh snapshot. M26 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01928 current scenarios/mysql/02-isolation/stable-snapshot.yaml:44 scenarios/mysql/02-isolation/stable-snapshot.yaml#steps[13].A A SELECT id, balance FROM accounts ORDER BY id M26 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01929 current scenarios/mysql/02-isolation/stable-snapshot.yaml:45 scenarios/mysql/02-isolation/stable-snapshot.yaml#steps[13].expect[0].id id 1 M26 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01930 current scenarios/mysql/02-isolation/stable-snapshot.yaml:45 scenarios/mysql/02-isolation/stable-snapshot.yaml#steps[13].expect[0].balance balance 999 M26 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01931 current scenarios/mysql/02-isolation/stable-snapshot.yaml:45 scenarios/mysql/02-isolation/stable-snapshot.yaml#steps[13].expect[1].id id 2 M26 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01932 current scenarios/mysql/02-isolation/stable-snapshot.yaml:45 scenarios/mysql/02-isolation/stable-snapshot.yaml#steps[13].expect[1].balance balance 60 M26 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01933 current scenarios/mysql/02-isolation/stable-snapshot.yaml:45 scenarios/mysql/02-isolation/stable-snapshot.yaml#steps[13].expect[2].id id 3 M26 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01934 current scenarios/mysql/02-isolation/stable-snapshot.yaml:45 scenarios/mysql/02-isolation/stable-snapshot.yaml#steps[13].expect[2].balance balance 300 M26 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01935 current scenarios/mysql/02-isolation/stable-snapshot.yaml:46 scenarios/mysql/02-isolation/stable-snapshot.yaml#steps[13].tl tl SELECT → 999 + carol (new snapshot) M26 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01936 current scenarios/mysql/02-isolation/update-recheck.yaml:1 scenarios/mysql/02-isolation/update-recheck.yaml#title title READ COMMITTED re-checks WHERE after waiting M27 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01937 current scenarios/mysql/02-isolation/update-recheck.yaml:2 scenarios/mysql/02-isolation/update-recheck.yaml#claim claim An UPDATE at READ COMMITTED that waited for a lock re-evaluates its WHERE clause against the new row version; rows that no longer match are silently skipped. M27 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01938 current scenarios/mysql/02-isolation/update-recheck.yaml:6 scenarios/mysql/02-isolation/update-recheck.yaml#setup setup "CREATE TABLE items (id int PRIMARY KEY, value int NOT NULL) ENGINE=InnoDB; INSERT INTO items VALUES (1, 10), (2, 30); " M27 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01939 current scenarios/mysql/02-isolation/update-recheck.yaml:9 scenarios/mysql/02-isolation/update-recheck.yaml#sessions[0] sessions[0] A M27 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01940 current scenarios/mysql/02-isolation/update-recheck.yaml:9 scenarios/mysql/02-isolation/update-recheck.yaml#sessions[1] sessions[1] B M27 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01941 current scenarios/mysql/02-isolation/update-recheck.yaml:11 scenarios/mysql/02-isolation/update-recheck.yaml#steps[0].A A BEGIN M27 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01942 current scenarios/mysql/02-isolation/update-recheck.yaml:12 scenarios/mysql/02-isolation/update-recheck.yaml#steps[1].A A UPDATE items SET value = value * 2 WHERE id = 1 M27 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01943 current scenarios/mysql/02-isolation/update-recheck.yaml:13 scenarios/mysql/02-isolation/update-recheck.yaml#steps[1].comment comment row 1: 10 → 20, uncommitted M27 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01944 current scenarios/mysql/02-isolation/update-recheck.yaml:14 scenarios/mysql/02-isolation/update-recheck.yaml#steps[1].tl tl UPDATE row1 → 20 (uncommitted) M27 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01945 current scenarios/mysql/02-isolation/update-recheck.yaml:16 scenarios/mysql/02-isolation/update-recheck.yaml#steps[2].note note B targets WHERE value = 10. The latest committed version of row 1 still qualifies; but it's locked by A, so B waits. M27 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01946 current scenarios/mysql/02-isolation/update-recheck.yaml:19 scenarios/mysql/02-isolation/update-recheck.yaml#steps[3].B B SET TRANSACTION ISOLATION LEVEL READ COMMITTED M27 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=READ COMMITTED, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01947 current scenarios/mysql/02-isolation/update-recheck.yaml:20 scenarios/mysql/02-isolation/update-recheck.yaml#steps[4].B B BEGIN M27 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=READ COMMITTED, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01948 current scenarios/mysql/02-isolation/update-recheck.yaml:21 scenarios/mysql/02-isolation/update-recheck.yaml#steps[5].B B UPDATE items SET value = 99 WHERE value = 10 M27 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01949 current scenarios/mysql/02-isolation/update-recheck.yaml:22 scenarios/mysql/02-isolation/update-recheck.yaml#steps[5].blocks blocks p1 M27 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01950 current scenarios/mysql/02-isolation/update-recheck.yaml:23 scenarios/mysql/02-isolation/update-recheck.yaml#steps[5].tl tl UPDATE WHERE value = 10 M27 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01951 current scenarios/mysql/02-isolation/update-recheck.yaml:25 scenarios/mysql/02-isolation/update-recheck.yaml#steps[6].note note A commits. B wakes up and re-checks the row it waited for against the NEW version, where value is 20. M27 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01952 current scenarios/mysql/02-isolation/update-recheck.yaml:28 scenarios/mysql/02-isolation/update-recheck.yaml#steps[7].A A COMMIT M27 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01953 current scenarios/mysql/02-isolation/update-recheck.yaml:29 scenarios/mysql/02-isolation/update-recheck.yaml#steps[7].tl tl COMMIT; row1 is now 20 M27 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01954 current scenarios/mysql/02-isolation/update-recheck.yaml:31 scenarios/mysql/02-isolation/update-recheck.yaml#steps[8].success success p1 M27 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01955 current scenarios/mysql/02-isolation/update-recheck.yaml:32 scenarios/mysql/02-isolation/update-recheck.yaml#steps[8].affected affected 0 M27 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01956 current scenarios/mysql/02-isolation/update-recheck.yaml:33 scenarios/mysql/02-isolation/update-recheck.yaml#steps[9].note note 0 rows affected; the row slipped away. M27 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01957 current scenarios/mysql/02-isolation/update-recheck.yaml:34 scenarios/mysql/02-isolation/update-recheck.yaml#steps[10].B B COMMIT M27 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=READ COMMITTED, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01958 current scenarios/mysql/02-isolation/update-recheck.yaml:36 scenarios/mysql/02-isolation/update-recheck.yaml#steps[11].B B SELECT id, value FROM items ORDER BY id M27 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01959 current scenarios/mysql/02-isolation/update-recheck.yaml:38 scenarios/mysql/02-isolation/update-recheck.yaml#steps[11].expect[0].id id 1 M27 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01960 current scenarios/mysql/02-isolation/update-recheck.yaml:38 scenarios/mysql/02-isolation/update-recheck.yaml#steps[11].expect[0].value value 20 M27 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01961 current scenarios/mysql/02-isolation/update-recheck.yaml:39 scenarios/mysql/02-isolation/update-recheck.yaml#steps[11].expect[1].id id 2 M27 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01962 current scenarios/mysql/02-isolation/update-recheck.yaml:39 scenarios/mysql/02-isolation/update-recheck.yaml#steps[11].expect[1].value value 30 M27 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01963 current scenarios/mysql/02-isolation/write-predicate-skew.yaml:1 scenarios/mysql/02-isolation/write-predicate-skew.yaml#title title Your DELETE and your SELECT live in different worlds M28 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01964 current scenarios/mysql/02-isolation/write-predicate-skew.yaml:2 scenarios/mysql/02-isolation/write-predicate-skew.yaml#claim claim In this InnoDB REPEATABLE READ schedule, A's DELETE of balance=20 finds no current matching row after B commits 15/25, while A's consistent SELECT still returns snapshot balance 20. The DELETE affects zero rows. M28 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01965 current scenarios/mysql/02-isolation/write-predicate-skew.yaml:6 scenarios/mysql/02-isolation/write-predicate-skew.yaml#setup setup "CREATE TABLE accounts (id int PRIMARY KEY, owner varchar(20) NOT NULL, balance int NOT NULL) ENGINE=InnoDB; INSERT INTO accounts VALUES (1, 'alice', 10), (2, 'bob', 20); " M28 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01966 current scenarios/mysql/02-isolation/write-predicate-skew.yaml:9 scenarios/mysql/02-isolation/write-predicate-skew.yaml#sessions[0] sessions[0] A M28 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01967 current scenarios/mysql/02-isolation/write-predicate-skew.yaml:9 scenarios/mysql/02-isolation/write-predicate-skew.yaml#sessions[1] sessions[1] B M28 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01968 current scenarios/mysql/02-isolation/write-predicate-skew.yaml:11 scenarios/mysql/02-isolation/write-predicate-skew.yaml#steps[0].A A SET TRANSACTION ISOLATION LEVEL REPEATABLE READ M28 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01969 current scenarios/mysql/02-isolation/write-predicate-skew.yaml:12 scenarios/mysql/02-isolation/write-predicate-skew.yaml#steps[1].note note A opens a snapshot. B then reshuffles every balance and commits. M28 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01970 current scenarios/mysql/02-isolation/write-predicate-skew.yaml:13 scenarios/mysql/02-isolation/write-predicate-skew.yaml#steps[2].A A BEGIN M28 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01971 current scenarios/mysql/02-isolation/write-predicate-skew.yaml:14 scenarios/mysql/02-isolation/write-predicate-skew.yaml#steps[3].A A SELECT id, balance FROM accounts ORDER BY id M28 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01972 current scenarios/mysql/02-isolation/write-predicate-skew.yaml:15 scenarios/mysql/02-isolation/write-predicate-skew.yaml#steps[3].expect[0].id id 1 M28 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01973 current scenarios/mysql/02-isolation/write-predicate-skew.yaml:15 scenarios/mysql/02-isolation/write-predicate-skew.yaml#steps[3].expect[0].balance balance 10 M28 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01974 current scenarios/mysql/02-isolation/write-predicate-skew.yaml:15 scenarios/mysql/02-isolation/write-predicate-skew.yaml#steps[3].expect[1].id id 2 M28 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01975 current scenarios/mysql/02-isolation/write-predicate-skew.yaml:15 scenarios/mysql/02-isolation/write-predicate-skew.yaml#steps[3].expect[1].balance balance 20 M28 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01976 current scenarios/mysql/02-isolation/write-predicate-skew.yaml:16 scenarios/mysql/02-isolation/write-predicate-skew.yaml#steps[3].comment comment snapshot taken M28 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01977 current scenarios/mysql/02-isolation/write-predicate-skew.yaml:17 scenarios/mysql/02-isolation/write-predicate-skew.yaml#steps[3].tl tl SELECT → 10, 20 (snapshot) M28 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01978 current scenarios/mysql/02-isolation/write-predicate-skew.yaml:19 scenarios/mysql/02-isolation/write-predicate-skew.yaml#steps[4].B B BEGIN M28 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01979 current scenarios/mysql/02-isolation/write-predicate-skew.yaml:20 scenarios/mysql/02-isolation/write-predicate-skew.yaml#steps[5].B B UPDATE accounts SET balance = balance + 5 M28 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01980 current scenarios/mysql/02-isolation/write-predicate-skew.yaml:21 scenarios/mysql/02-isolation/write-predicate-skew.yaml#steps[5].tl tl +5 to every balance M28 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01981 current scenarios/mysql/02-isolation/write-predicate-skew.yaml:22 scenarios/mysql/02-isolation/write-predicate-skew.yaml#steps[6].B B COMMIT M28 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01982 current scenarios/mysql/02-isolation/write-predicate-skew.yaml:23 scenarios/mysql/02-isolation/write-predicate-skew.yaml#steps[6].comment comment current data is now 15 and 25 M28 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01983 current scenarios/mysql/02-isolation/write-predicate-skew.yaml:24 scenarios/mysql/02-isolation/write-predicate-skew.yaml#steps[6].tl tl COMMIT (now 15, 25) M28 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01984 current scenarios/mysql/02-isolation/write-predicate-skew.yaml:26 scenarios/mysql/02-isolation/write-predicate-skew.yaml#steps[7].note note A closes every account with balance 20; its snapshot says that's bob. But the DELETE is a current read: it scans the committed 15 and 25, finds nothing, and deletes nothing. M28 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01985 current scenarios/mysql/02-isolation/write-predicate-skew.yaml:30 scenarios/mysql/02-isolation/write-predicate-skew.yaml#steps[8].A A DELETE FROM accounts WHERE balance = 20 M28 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01986 current scenarios/mysql/02-isolation/write-predicate-skew.yaml:31 scenarios/mysql/02-isolation/write-predicate-skew.yaml#steps[8].affected affected 0 M28 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01987 current scenarios/mysql/02-isolation/write-predicate-skew.yaml:32 scenarios/mysql/02-isolation/write-predicate-skew.yaml#steps[8].tl tl DELETE balance = 20 → 0 rows M28 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01988 current scenarios/mysql/02-isolation/write-predicate-skew.yaml:34 scenarios/mysql/02-isolation/write-predicate-skew.yaml#steps[9].A A SELECT id, balance FROM accounts WHERE balance = 20 ORDER BY id M28 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01989 current scenarios/mysql/02-isolation/write-predicate-skew.yaml:35 scenarios/mysql/02-isolation/write-predicate-skew.yaml#steps[9].expect[0].id id 2 M28 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01990 current scenarios/mysql/02-isolation/write-predicate-skew.yaml:35 scenarios/mysql/02-isolation/write-predicate-skew.yaml#steps[9].expect[0].balance balance 20 M28 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01991 current scenarios/mysql/02-isolation/write-predicate-skew.yaml:36 scenarios/mysql/02-isolation/write-predicate-skew.yaml#steps[9].comment comment …yet A still SEES a row with balance 20. Deleted: no such rows. Visible: one. M28 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01992 current scenarios/mysql/02-isolation/write-predicate-skew.yaml:37 scenarios/mysql/02-isolation/write-predicate-skew.yaml#steps[9].tl tl SELECT balance = 20 → still sees bob M28 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01993 current scenarios/mysql/02-isolation/write-predicate-skew.yaml:38 scenarios/mysql/02-isolation/write-predicate-skew.yaml#steps[10].A A COMMIT M28 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01994 current scenarios/mysql/02-isolation/write-predicate-skew.yaml:40 scenarios/mysql/02-isolation/write-predicate-skew.yaml#steps[11].note note A's DELETE used current rows while its consistent SELECT retained an older snapshot. A locking read must precede the decision and all relevant writers must coordinate; changing a later read alone is not a general repair. See the locking and SERIALIZABLE lessons. M28 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01995 current scenarios/mysql/02-isolation/write-skew-rr.yaml:1 scenarios/mysql/02-isolation/write-skew-rr.yaml#title title Write skew: REPEATABLE READ is not enough M29 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01996 current scenarios/mysql/02-isolation/write-skew-rr.yaml:2 scenarios/mysql/02-isolation/write-skew-rr.yaml#claim claim Two REPEATABLE READ transactions can each validate an invariant against their snapshots, write to different rows, and both commit; leaving the invariant broken. This is write skew. M29 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01997 current scenarios/mysql/02-isolation/write-skew-rr.yaml:6 scenarios/mysql/02-isolation/write-skew-rr.yaml#anomaly anomaly G2-item M29 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01998 current scenarios/mysql/02-isolation/write-skew-rr.yaml:7 scenarios/mysql/02-isolation/write-skew-rr.yaml#isolation isolation REPEATABLE READ M29 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C01999 current scenarios/mysql/02-isolation/write-skew-rr.yaml:8 scenarios/mysql/02-isolation/write-skew-rr.yaml#setup setup "CREATE TABLE doctors (name varchar(20) PRIMARY KEY, on_call boolean NOT NULL) ENGINE=InnoDB; INSERT INTO doctors VALUES ('alice', true), ('bob', true); " M29 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02000 current scenarios/mysql/02-isolation/write-skew-rr.yaml:11 scenarios/mysql/02-isolation/write-skew-rr.yaml#sessions[0] sessions[0] A M29 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02001 current scenarios/mysql/02-isolation/write-skew-rr.yaml:11 scenarios/mysql/02-isolation/write-skew-rr.yaml#sessions[1] sessions[1] B M29 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02002 current scenarios/mysql/02-isolation/write-skew-rr.yaml:13 scenarios/mysql/02-isolation/write-skew-rr.yaml#steps[0].A A SET TRANSACTION ISOLATION LEVEL REPEATABLE READ M29 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02003 current scenarios/mysql/02-isolation/write-skew-rr.yaml:14 scenarios/mysql/02-isolation/write-skew-rr.yaml#steps[1].B B SET TRANSACTION ISOLATION LEVEL REPEATABLE READ M29 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02004 current scenarios/mysql/02-isolation/write-skew-rr.yaml:15 scenarios/mysql/02-isolation/write-skew-rr.yaml#steps[2].note note Hospital rule: at least one doctor must stay on call. Alice and Bob both want the night off. M29 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02005 current scenarios/mysql/02-isolation/write-skew-rr.yaml:18 scenarios/mysql/02-isolation/write-skew-rr.yaml#steps[3].A A BEGIN M29 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02006 current scenarios/mysql/02-isolation/write-skew-rr.yaml:19 scenarios/mysql/02-isolation/write-skew-rr.yaml#steps[4].B B BEGIN M29 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02007 current scenarios/mysql/02-isolation/write-skew-rr.yaml:21 scenarios/mysql/02-isolation/write-skew-rr.yaml#steps[5].A A SELECT count(*) AS on_call FROM doctors WHERE on_call M29 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02008 current scenarios/mysql/02-isolation/write-skew-rr.yaml:22 scenarios/mysql/02-isolation/write-skew-rr.yaml#steps[5].expect[0].on_call on_call 2 M29 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02009 current scenarios/mysql/02-isolation/write-skew-rr.yaml:23 scenarios/mysql/02-isolation/write-skew-rr.yaml#steps[5].comment comment """two of us; safe for me to leave""" M29 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02010 current scenarios/mysql/02-isolation/write-skew-rr.yaml:24 scenarios/mysql/02-isolation/write-skew-rr.yaml#steps[5].tl tl on-call count → 2 M29 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02011 current scenarios/mysql/02-isolation/write-skew-rr.yaml:26 scenarios/mysql/02-isolation/write-skew-rr.yaml#steps[6].B B SELECT count(*) AS on_call FROM doctors WHERE on_call M29 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02012 current scenarios/mysql/02-isolation/write-skew-rr.yaml:27 scenarios/mysql/02-isolation/write-skew-rr.yaml#steps[6].expect[0].on_call on_call 2 M29 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02013 current scenarios/mysql/02-isolation/write-skew-rr.yaml:28 scenarios/mysql/02-isolation/write-skew-rr.yaml#steps[6].comment comment """two of us; safe for me to leave""" M29 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02014 current scenarios/mysql/02-isolation/write-skew-rr.yaml:29 scenarios/mysql/02-isolation/write-skew-rr.yaml#steps[6].tl tl on-call count → 2 M29 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02015 current scenarios/mysql/02-isolation/write-skew-rr.yaml:31 scenarios/mysql/02-isolation/write-skew-rr.yaml#steps[7].note note Each updates a DIFFERENT row, so there is no write-write conflict to detect. M29 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02016 current scenarios/mysql/02-isolation/write-skew-rr.yaml:32 scenarios/mysql/02-isolation/write-skew-rr.yaml#steps[8].A A UPDATE doctors SET on_call = false WHERE name = 'alice' M29 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02017 current scenarios/mysql/02-isolation/write-skew-rr.yaml:33 scenarios/mysql/02-isolation/write-skew-rr.yaml#steps[8].tl tl alice off call M29 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02018 current scenarios/mysql/02-isolation/write-skew-rr.yaml:34 scenarios/mysql/02-isolation/write-skew-rr.yaml#steps[9].B B UPDATE doctors SET on_call = false WHERE name = 'bob' M29 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02019 current scenarios/mysql/02-isolation/write-skew-rr.yaml:35 scenarios/mysql/02-isolation/write-skew-rr.yaml#steps[9].tl tl bob off call M29 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02020 current scenarios/mysql/02-isolation/write-skew-rr.yaml:37 scenarios/mysql/02-isolation/write-skew-rr.yaml#steps[10].A A COMMIT M29 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02021 current scenarios/mysql/02-isolation/write-skew-rr.yaml:38 scenarios/mysql/02-isolation/write-skew-rr.yaml#steps[10].tl tl COMMIT M29 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, open transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02022 current scenarios/mysql/02-isolation/write-skew-rr.yaml:39 scenarios/mysql/02-isolation/write-skew-rr.yaml#steps[11].B B COMMIT M29 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02023 current scenarios/mysql/02-isolation/write-skew-rr.yaml:40 scenarios/mysql/02-isolation/write-skew-rr.yaml#steps[11].comment comment both succeed! M29 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02024 current scenarios/mysql/02-isolation/write-skew-rr.yaml:41 scenarios/mysql/02-isolation/write-skew-rr.yaml#steps[11].tl tl COMMIT (both succeed) M29 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02025 current scenarios/mysql/02-isolation/write-skew-rr.yaml:43 scenarios/mysql/02-isolation/write-skew-rr.yaml#steps[12].A A SELECT count(*) AS on_call FROM doctors WHERE on_call M29 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02026 current scenarios/mysql/02-isolation/write-skew-rr.yaml:44 scenarios/mysql/02-isolation/write-skew-rr.yaml#steps[12].expect[0].on_call on_call 0 M29 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02027 current scenarios/mysql/02-isolation/write-skew-rr.yaml:45 scenarios/mysql/02-isolation/write-skew-rr.yaml#steps[12].comment comment nobody is on call; the invariant is broken M29 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02028 current scenarios/mysql/02-isolation/write-skew-rr.yaml:46 scenarios/mysql/02-isolation/write-skew-rr.yaml#steps[12].tl tl on-call count → 0; invariant broken M29 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02029 current scenarios/mysql/02-isolation/write-skew-rr.yaml:48 scenarios/mysql/02-isolation/write-skew-rr.yaml#steps[13].note note Each transaction was internally consistent; together they broke the rule. SERIALIZABLE or suitable coordination by all relevant writers can protect it; the next Scenario executes the SERIALIZABLE schedule. M29 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02030 current scenarios/mysql/02-isolation/write-skew-serializable.yaml:1 scenarios/mysql/02-isolation/write-skew-serializable.yaml#title title SERIALIZABLE catches write skew; with locks M30 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02031 current scenarios/mysql/02-isolation/write-skew-serializable.yaml:2 scenarios/mysql/02-isolation/write-skew-serializable.yaml#claim claim In these explicit InnoDB SERIALIZABLE transactions with deadlock detection enabled, the count SELECTs take shared locks. This schedule rejects B's UPDATE with 1213, A commits, and a fresh B attempt sees one doctor and declines to leave. Other schedules need not select B as victim. M30 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02032 current scenarios/mysql/02-isolation/write-skew-serializable.yaml:7 scenarios/mysql/02-isolation/write-skew-serializable.yaml#anomaly anomaly G2-item M30 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02033 current scenarios/mysql/02-isolation/write-skew-serializable.yaml:8 scenarios/mysql/02-isolation/write-skew-serializable.yaml#isolation isolation SERIALIZABLE M30 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02034 current scenarios/mysql/02-isolation/write-skew-serializable.yaml:9 scenarios/mysql/02-isolation/write-skew-serializable.yaml#setup setup "CREATE TABLE doctors (name varchar(20) PRIMARY KEY, on_call boolean NOT NULL) ENGINE=InnoDB; INSERT INTO doctors VALUES ('alice', true), ('bob', true); " M30 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02035 current scenarios/mysql/02-isolation/write-skew-serializable.yaml:12 scenarios/mysql/02-isolation/write-skew-serializable.yaml#sessions[0] sessions[0] A M30 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02036 current scenarios/mysql/02-isolation/write-skew-serializable.yaml:12 scenarios/mysql/02-isolation/write-skew-serializable.yaml#sessions[1] sessions[1] B M30 MySQL 8.4.11, InnoDB; entire schedule, exact per-step transaction scopes in registry; operation/expected value as recorded Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02037 current scenarios/mysql/02-isolation/write-skew-serializable.yaml:14 scenarios/mysql/02-isolation/write-skew-serializable.yaml#steps[0].A A SELECT @@innodb_deadlock_detect AS deadlock_detect M30 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02038 current scenarios/mysql/02-isolation/write-skew-serializable.yaml:15 scenarios/mysql/02-isolation/write-skew-serializable.yaml#steps[0].expect[0].deadlock_detect deadlock_detect 1 M30 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02039 current scenarios/mysql/02-isolation/write-skew-serializable.yaml:16 scenarios/mysql/02-isolation/write-skew-serializable.yaml#steps[1].note note Same story, same statements, same order; only the isolation level differs. M30 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02040 current scenarios/mysql/02-isolation/write-skew-serializable.yaml:17 scenarios/mysql/02-isolation/write-skew-serializable.yaml#steps[2].A A SET TRANSACTION ISOLATION LEVEL SERIALIZABLE M30 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=SERIALIZABLE, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02041 current scenarios/mysql/02-isolation/write-skew-serializable.yaml:18 scenarios/mysql/02-isolation/write-skew-serializable.yaml#steps[3].B B SET TRANSACTION ISOLATION LEVEL SERIALIZABLE M30 MySQL 8.4.11, InnoDB; before step: A=SERIALIZABLE, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=SERIALIZABLE, standalone/next transaction, autocommit=1; B=SERIALIZABLE, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02042 current scenarios/mysql/02-isolation/write-skew-serializable.yaml:19 scenarios/mysql/02-isolation/write-skew-serializable.yaml#steps[4].A A BEGIN M30 MySQL 8.4.11, InnoDB; before step: A=SERIALIZABLE, standalone/next transaction, autocommit=1; B=SERIALIZABLE, standalone/next transaction, autocommit=1; operation/expected value as recorded A=SERIALIZABLE, open transaction, autocommit=1; B=SERIALIZABLE, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02043 current scenarios/mysql/02-isolation/write-skew-serializable.yaml:20 scenarios/mysql/02-isolation/write-skew-serializable.yaml#steps[5].B B BEGIN M30 MySQL 8.4.11, InnoDB; before step: A=SERIALIZABLE, open transaction, autocommit=1; B=SERIALIZABLE, standalone/next transaction, autocommit=1; operation/expected value as recorded A=SERIALIZABLE, open transaction, autocommit=1; B=SERIALIZABLE, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02044 current scenarios/mysql/02-isolation/write-skew-serializable.yaml:22 scenarios/mysql/02-isolation/write-skew-serializable.yaml#steps[6].A A SELECT count(*) AS on_call FROM doctors WHERE on_call M30 MySQL 8.4.11, InnoDB; before step: A=SERIALIZABLE, open transaction, autocommit=1; B=SERIALIZABLE, open transaction, autocommit=1; operation/expected value as recorded A=SERIALIZABLE, open transaction, autocommit=1; B=SERIALIZABLE, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02045 current scenarios/mysql/02-isolation/write-skew-serializable.yaml:23 scenarios/mysql/02-isolation/write-skew-serializable.yaml#steps[6].expect[0].on_call on_call 2 M30 MySQL 8.4.11, InnoDB; before step: A=SERIALIZABLE, open transaction, autocommit=1; B=SERIALIZABLE, open transaction, autocommit=1; operation/expected value as recorded A=SERIALIZABLE, open transaction, autocommit=1; B=SERIALIZABLE, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02046 current scenarios/mysql/02-isolation/write-skew-serializable.yaml:24 scenarios/mysql/02-isolation/write-skew-serializable.yaml#steps[6].tl tl on-call count → 2 (takes shared locks) M30 MySQL 8.4.11, InnoDB; before step: A=SERIALIZABLE, open transaction, autocommit=1; B=SERIALIZABLE, open transaction, autocommit=1; operation/expected value as recorded A=SERIALIZABLE, open transaction, autocommit=1; B=SERIALIZABLE, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02047 current scenarios/mysql/02-isolation/write-skew-serializable.yaml:26 scenarios/mysql/02-isolation/write-skew-serializable.yaml#steps[7].B B SELECT count(*) AS on_call FROM doctors WHERE on_call M30 MySQL 8.4.11, InnoDB; before step: A=SERIALIZABLE, open transaction, autocommit=1; B=SERIALIZABLE, open transaction, autocommit=1; operation/expected value as recorded A=SERIALIZABLE, open transaction, autocommit=1; B=SERIALIZABLE, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02048 current scenarios/mysql/02-isolation/write-skew-serializable.yaml:27 scenarios/mysql/02-isolation/write-skew-serializable.yaml#steps[7].expect[0].on_call on_call 2 M30 MySQL 8.4.11, InnoDB; before step: A=SERIALIZABLE, open transaction, autocommit=1; B=SERIALIZABLE, open transaction, autocommit=1; operation/expected value as recorded A=SERIALIZABLE, open transaction, autocommit=1; B=SERIALIZABLE, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02049 current scenarios/mysql/02-isolation/write-skew-serializable.yaml:28 scenarios/mysql/02-isolation/write-skew-serializable.yaml#steps[7].tl tl on-call count → 2 (takes shared locks) M30 MySQL 8.4.11, InnoDB; before step: A=SERIALIZABLE, open transaction, autocommit=1; B=SERIALIZABLE, open transaction, autocommit=1; operation/expected value as recorded A=SERIALIZABLE, open transaction, autocommit=1; B=SERIALIZABLE, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02050 current scenarios/mysql/02-isolation/write-skew-serializable.yaml:30 scenarios/mysql/02-isolation/write-skew-serializable.yaml#steps[8].note note Those SELECTs took shared locks on the rows they read. A's write now waits for B… M30 MySQL 8.4.11, InnoDB; before step: A=SERIALIZABLE, open transaction, autocommit=1; B=SERIALIZABLE, open transaction, autocommit=1; operation/expected value as recorded A=SERIALIZABLE, open transaction, autocommit=1; B=SERIALIZABLE, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02051 current scenarios/mysql/02-isolation/write-skew-serializable.yaml:31 scenarios/mysql/02-isolation/write-skew-serializable.yaml#steps[9].A A UPDATE doctors SET on_call = false WHERE name = 'alice' M30 MySQL 8.4.11, InnoDB; before step: A=SERIALIZABLE, open transaction, autocommit=1; B=SERIALIZABLE, open transaction, autocommit=1; operation/expected value as recorded A=SERIALIZABLE, open transaction, autocommit=1; B=SERIALIZABLE, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02052 current scenarios/mysql/02-isolation/write-skew-serializable.yaml:32 scenarios/mysql/02-isolation/write-skew-serializable.yaml#steps[9].blocks blocks p1 M30 MySQL 8.4.11, InnoDB; before step: A=SERIALIZABLE, open transaction, autocommit=1; B=SERIALIZABLE, open transaction, autocommit=1; operation/expected value as recorded A=SERIALIZABLE, open transaction, autocommit=1; B=SERIALIZABLE, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02053 current scenarios/mysql/02-isolation/write-skew-serializable.yaml:33 scenarios/mysql/02-isolation/write-skew-serializable.yaml#steps[9].tl tl alice off call M30 MySQL 8.4.11, InnoDB; before step: A=SERIALIZABLE, open transaction, autocommit=1; B=SERIALIZABLE, open transaction, autocommit=1; operation/expected value as recorded A=SERIALIZABLE, open transaction, autocommit=1; B=SERIALIZABLE, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02054 current scenarios/mysql/02-isolation/write-skew-serializable.yaml:35 scenarios/mysql/02-isolation/write-skew-serializable.yaml#steps[10].note note …and B's write closes the cycle. InnoDB detects the deadlock and rolls B back entirely. M30 MySQL 8.4.11, InnoDB; before step: A=SERIALIZABLE, open transaction, autocommit=1; B=SERIALIZABLE, open transaction, autocommit=1; operation/expected value as recorded A=SERIALIZABLE, open transaction, autocommit=1; B=SERIALIZABLE, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02055 current scenarios/mysql/02-isolation/write-skew-serializable.yaml:36 scenarios/mysql/02-isolation/write-skew-serializable.yaml#steps[11].B.fails fails UPDATE doctors SET on_call = false WHERE name = 'bob' M30 MySQL 8.4.11, InnoDB; before step: A=SERIALIZABLE, open transaction, autocommit=1; B=SERIALIZABLE, open transaction, autocommit=1; operation/expected value as recorded A=SERIALIZABLE, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02056 current scenarios/mysql/02-isolation/write-skew-serializable.yaml:37 scenarios/mysql/02-isolation/write-skew-serializable.yaml#steps[11].error error 1213 M30 MySQL 8.4.11, InnoDB; before step: A=SERIALIZABLE, open transaction, autocommit=1; B=SERIALIZABLE, open transaction, autocommit=1; operation/expected value as recorded A=SERIALIZABLE, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02057 current scenarios/mysql/02-isolation/write-skew-serializable.yaml:38 scenarios/mysql/02-isolation/write-skew-serializable.yaml#steps[11].comment comment ER_LOCK_DEADLOCK M30 MySQL 8.4.11, InnoDB; before step: A=SERIALIZABLE, open transaction, autocommit=1; B=SERIALIZABLE, open transaction, autocommit=1; operation/expected value as recorded A=SERIALIZABLE, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02058 current scenarios/mysql/02-isolation/write-skew-serializable.yaml:39 scenarios/mysql/02-isolation/write-skew-serializable.yaml#steps[11].tl tl bob off call M30 MySQL 8.4.11, InnoDB; before step: A=SERIALIZABLE, open transaction, autocommit=1; B=SERIALIZABLE, open transaction, autocommit=1; operation/expected value as recorded A=SERIALIZABLE, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02059 current scenarios/mysql/02-isolation/write-skew-serializable.yaml:41 scenarios/mysql/02-isolation/write-skew-serializable.yaml#steps[12].note note B's rollback freed the locks; A's update proceeds. M30 MySQL 8.4.11, InnoDB; before step: A=SERIALIZABLE, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=SERIALIZABLE, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02060 current scenarios/mysql/02-isolation/write-skew-serializable.yaml:42 scenarios/mysql/02-isolation/write-skew-serializable.yaml#steps[13].success success p1 M30 MySQL 8.4.11, InnoDB; before step: A=SERIALIZABLE, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=SERIALIZABLE, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02061 current scenarios/mysql/02-isolation/write-skew-serializable.yaml:43 scenarios/mysql/02-isolation/write-skew-serializable.yaml#steps[14].A A COMMIT M30 MySQL 8.4.11, InnoDB; before step: A=SERIALIZABLE, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02062 current scenarios/mysql/02-isolation/write-skew-serializable.yaml:44 scenarios/mysql/02-isolation/write-skew-serializable.yaml#steps[14].tl tl COMMIT M30 MySQL 8.4.11, InnoDB; before step: A=SERIALIZABLE, open transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02063 current scenarios/mysql/02-isolation/write-skew-serializable.yaml:46 scenarios/mysql/02-isolation/write-skew-serializable.yaml#steps[15].A A SELECT count(*) AS on_call FROM doctors WHERE on_call M30 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02064 current scenarios/mysql/02-isolation/write-skew-serializable.yaml:47 scenarios/mysql/02-isolation/write-skew-serializable.yaml#steps[15].expect[0].on_call on_call 1 M30 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02065 current scenarios/mysql/02-isolation/write-skew-serializable.yaml:48 scenarios/mysql/02-isolation/write-skew-serializable.yaml#steps[15].comment comment the invariant survived M30 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02066 current scenarios/mysql/02-isolation/write-skew-serializable.yaml:49 scenarios/mysql/02-isolation/write-skew-serializable.yaml#steps[15].tl tl on-call count → 1; invariant survived M30 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02067 current scenarios/mysql/02-isolation/write-skew-serializable.yaml:51 scenarios/mysql/02-isolation/write-skew-serializable.yaml#steps[16].note note B starts a fresh SERIALIZABLE transaction and repeats the count. With only one doctor remaining, the application declines the update. M30 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02068 current scenarios/mysql/02-isolation/write-skew-serializable.yaml:54 scenarios/mysql/02-isolation/write-skew-serializable.yaml#steps[17].B B SET TRANSACTION ISOLATION LEVEL SERIALIZABLE M30 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=SERIALIZABLE, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02069 current scenarios/mysql/02-isolation/write-skew-serializable.yaml:55 scenarios/mysql/02-isolation/write-skew-serializable.yaml#steps[18].B B BEGIN M30 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=SERIALIZABLE, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=SERIALIZABLE, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02070 current scenarios/mysql/02-isolation/write-skew-serializable.yaml:56 scenarios/mysql/02-isolation/write-skew-serializable.yaml#steps[19].B B SELECT count(*) AS on_call FROM doctors WHERE on_call M30 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=SERIALIZABLE, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=SERIALIZABLE, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02071 current scenarios/mysql/02-isolation/write-skew-serializable.yaml:57 scenarios/mysql/02-isolation/write-skew-serializable.yaml#steps[19].expect[0].on_call on_call 1 M30 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=SERIALIZABLE, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=SERIALIZABLE, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02072 current scenarios/mysql/02-isolation/write-skew-serializable.yaml:58 scenarios/mysql/02-isolation/write-skew-serializable.yaml#steps[20].B B COMMIT M30 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=SERIALIZABLE, open transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02073 current scenarios/mysql/02-isolation/write-skew-serializable.yaml:59 scenarios/mysql/02-isolation/write-skew-serializable.yaml#steps[21].A A SELECT name, on_call FROM doctors ORDER BY name M30 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02074 current scenarios/mysql/02-isolation/write-skew-serializable.yaml:60 scenarios/mysql/02-isolation/write-skew-serializable.yaml#steps[21].expect[0].name name alice M30 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02075 current scenarios/mysql/02-isolation/write-skew-serializable.yaml:60 scenarios/mysql/02-isolation/write-skew-serializable.yaml#steps[21].expect[0].on_call on_call 0 M30 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02076 current scenarios/mysql/02-isolation/write-skew-serializable.yaml:60 scenarios/mysql/02-isolation/write-skew-serializable.yaml#steps[21].expect[1].name name bob M30 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02077 current scenarios/mysql/02-isolation/write-skew-serializable.yaml:60 scenarios/mysql/02-isolation/write-skew-serializable.yaml#steps[21].expect[1].on_call on_call 1 M30 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02078 current scenarios/mysql/02-isolation/write-skew-serializable.yaml:62 scenarios/mysql/02-isolation/write-skew-serializable.yaml#steps[22].note note A standalone SERIALIZABLE SELECT with autocommit=1 is a nonlocking consistent read here. M30 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02079 current scenarios/mysql/02-isolation/write-skew-serializable.yaml:63 scenarios/mysql/02-isolation/write-skew-serializable.yaml#steps[23].A A SET SESSION TRANSACTION ISOLATION LEVEL SERIALIZABLE M30 MySQL 8.4.11, InnoDB; before step: A=REPEATABLE READ, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=SERIALIZABLE, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02080 current scenarios/mysql/02-isolation/write-skew-serializable.yaml:64 scenarios/mysql/02-isolation/write-skew-serializable.yaml#steps[24].A A SELECT @@autocommit AS autocommit M30 MySQL 8.4.11, InnoDB; before step: A=SERIALIZABLE, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=SERIALIZABLE, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02081 current scenarios/mysql/02-isolation/write-skew-serializable.yaml:65 scenarios/mysql/02-isolation/write-skew-serializable.yaml#steps[24].expect[0].autocommit autocommit 1 M30 MySQL 8.4.11, InnoDB; before step: A=SERIALIZABLE, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=SERIALIZABLE, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02082 current scenarios/mysql/02-isolation/write-skew-serializable.yaml:66 scenarios/mysql/02-isolation/write-skew-serializable.yaml#steps[25].B B BEGIN M30 MySQL 8.4.11, InnoDB; before step: A=SERIALIZABLE, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=SERIALIZABLE, standalone/next transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02083 current scenarios/mysql/02-isolation/write-skew-serializable.yaml:67 scenarios/mysql/02-isolation/write-skew-serializable.yaml#steps[26].B B UPDATE doctors SET on_call = false WHERE name = 'bob' M30 MySQL 8.4.11, InnoDB; before step: A=SERIALIZABLE, standalone/next transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=SERIALIZABLE, standalone/next transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02084 current scenarios/mysql/02-isolation/write-skew-serializable.yaml:68 scenarios/mysql/02-isolation/write-skew-serializable.yaml#steps[27].A A SELECT count(*) AS on_call FROM doctors WHERE on_call M30 MySQL 8.4.11, InnoDB; before step: A=SERIALIZABLE, standalone/next transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=SERIALIZABLE, standalone/next transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02085 current scenarios/mysql/02-isolation/write-skew-serializable.yaml:69 scenarios/mysql/02-isolation/write-skew-serializable.yaml#steps[27].expect[0].on_call on_call 1 M30 MySQL 8.4.11, InnoDB; before step: A=SERIALIZABLE, standalone/next transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=SERIALIZABLE, standalone/next transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02086 current scenarios/mysql/02-isolation/write-skew-serializable.yaml:71 scenarios/mysql/02-isolation/write-skew-serializable.yaml#steps[28].note note With autocommit=0, A's SERIALIZABLE SELECT instead waits for B's row lock. M30 MySQL 8.4.11, InnoDB; before step: A=SERIALIZABLE, standalone/next transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=SERIALIZABLE, standalone/next transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1 Demonstrated schedule narration, scoped by source; referenced contracts separately in registry/lesson Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02087 current scenarios/mysql/02-isolation/write-skew-serializable.yaml:72 scenarios/mysql/02-isolation/write-skew-serializable.yaml#steps[29].A A SET autocommit = 0 M30 MySQL 8.4.11, InnoDB; before step: A=SERIALIZABLE, standalone/next transaction, autocommit=1; B=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=SERIALIZABLE, implicit transaction mode, autocommit=0; B=REPEATABLE READ, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02088 current scenarios/mysql/02-isolation/write-skew-serializable.yaml:73 scenarios/mysql/02-isolation/write-skew-serializable.yaml#steps[30].A A SELECT count(*) AS on_call FROM doctors WHERE on_call M30 MySQL 8.4.11, InnoDB; before step: A=SERIALIZABLE, implicit transaction mode, autocommit=0; B=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=SERIALIZABLE, open transaction, autocommit=0; B=REPEATABLE READ, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02089 current scenarios/mysql/02-isolation/write-skew-serializable.yaml:74 scenarios/mysql/02-isolation/write-skew-serializable.yaml#steps[30].blocks blocks p2 M30 MySQL 8.4.11, InnoDB; before step: A=SERIALIZABLE, implicit transaction mode, autocommit=0; B=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=SERIALIZABLE, open transaction, autocommit=0; B=REPEATABLE READ, open transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02090 current scenarios/mysql/02-isolation/write-skew-serializable.yaml:75 scenarios/mysql/02-isolation/write-skew-serializable.yaml#steps[31].B B ROLLBACK M30 MySQL 8.4.11, InnoDB; before step: A=SERIALIZABLE, open transaction, autocommit=0; B=REPEATABLE READ, open transaction, autocommit=1; operation/expected value as recorded A=SERIALIZABLE, open transaction, autocommit=0; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02091 current scenarios/mysql/02-isolation/write-skew-serializable.yaml:76 scenarios/mysql/02-isolation/write-skew-serializable.yaml#steps[32].success success p2 M30 MySQL 8.4.11, InnoDB; before step: A=SERIALIZABLE, open transaction, autocommit=0; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=SERIALIZABLE, open transaction, autocommit=0; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02092 current scenarios/mysql/02-isolation/write-skew-serializable.yaml:77 scenarios/mysql/02-isolation/write-skew-serializable.yaml#steps[32].expect[0].on_call on_call 1 M30 MySQL 8.4.11, InnoDB; before step: A=SERIALIZABLE, open transaction, autocommit=0; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=SERIALIZABLE, open transaction, autocommit=0; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02093 current scenarios/mysql/02-isolation/write-skew-serializable.yaml:78 scenarios/mysql/02-isolation/write-skew-serializable.yaml#steps[33].A A ROLLBACK M30 MySQL 8.4.11, InnoDB; before step: A=SERIALIZABLE, open transaction, autocommit=0; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=SERIALIZABLE, implicit transaction mode, autocommit=0; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02094 current scenarios/mysql/02-isolation/write-skew-serializable.yaml:79 scenarios/mysql/02-isolation/write-skew-serializable.yaml#steps[34].A A SET autocommit = 1 M30 MySQL 8.4.11, InnoDB; before step: A=SERIALIZABLE, implicit transaction mode, autocommit=0; B=REPEATABLE READ, standalone/next transaction, autocommit=1; operation/expected value as recorded A=SERIALIZABLE, standalone/next transaction, autocommit=1; B=REPEATABLE READ, standalone/next transaction, autocommit=1 Executable setup/step/assertion or metadata, not an all-schedule guarantee Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02095 current docs/mysql/01-basics/parts/aborted-transaction.md:1 scenarios/mysql/01-basics/aborted-transaction.yaml#Transcript.lines[1..32] generated-mirror Complete SQL/status/results, narrator paragraphs, timeline labels and verification footer, lines 1-32; claims are the exact source-field occurrences inventoried separately M10 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Demonstrated schedule mirror, not independent all-schedule evidence Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02096 current docs/public/ledger.jsonl:1 scenarios/mysql/01-basics/aborted-transaction.yaml#ledger.scenario ledger-field """mysql/01-basics/aborted-transaction.yaml""" M10 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02097 current docs/public/ledger.jsonl:1 scenarios/mysql/01-basics/aborted-transaction.yaml#ledger.engine ledger-field """mysql""" M10 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02098 current docs/public/ledger.jsonl:1 scenarios/mysql/01-basics/aborted-transaction.yaml#ledger.product ledger-field """MySQL""" M10 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02099 current docs/public/ledger.jsonl:1 scenarios/mysql/01-basics/aborted-transaction.yaml#ledger.version ledger-field """8.4.11""" M10 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02100 current docs/public/ledger.jsonl:1 scenarios/mysql/01-basics/aborted-transaction.yaml#ledger.claim ledger-field """The demonstrated duplicate-key INSERT error (1062, without IGNORE) rolls back that statement; the earlier and later INSERTs commit in the same InnoDB transaction. This does not describe deadlock or connection errors.""" M10 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02101 current docs/public/ledger.jsonl:1 scenarios/mysql/01-basics/aborted-transaction.yaml#ledger.sessions ledger-field "[""A""]" M10 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02102 current docs/public/ledger.jsonl:1 scenarios/mysql/01-basics/aborted-transaction.yaml#ledger.errors ledger-field "[""1062""]" M10 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02103 current docs/public/llms-full.txt:6 scenarios/mysql/01-basics/aborted-transaction.yaml#llms.section.lines[6..41] llms-mirror Complete attributed section, lines 6-41; metadata and Transcript mirror for this exact schedule, source-field claims inventoried separately M10 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated mirror, same support as its exact Transcript and source fields Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02104 current docs/mysql/01-basics/parts/atomicity.md:1 scenarios/mysql/01-basics/atomicity.yaml#Transcript.lines[1..55] generated-mirror Complete SQL/status/results, narrator paragraphs, timeline labels and verification footer, lines 1-55; claims are the exact source-field occurrences inventoried separately M11 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Demonstrated schedule mirror, not independent all-schedule evidence Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02105 current docs/public/ledger.jsonl:2 scenarios/mysql/01-basics/atomicity.yaml#ledger.scenario ledger-field """mysql/01-basics/atomicity.yaml""" M11 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02106 current docs/public/ledger.jsonl:2 scenarios/mysql/01-basics/atomicity.yaml#ledger.engine ledger-field """mysql""" M11 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02107 current docs/public/ledger.jsonl:2 scenarios/mysql/01-basics/atomicity.yaml#ledger.product ledger-field """MySQL""" M11 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02108 current docs/public/ledger.jsonl:2 scenarios/mysql/01-basics/atomicity.yaml#ledger.version ledger-field """8.4.11""" M11 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02109 current docs/public/ledger.jsonl:2 scenarios/mysql/01-basics/atomicity.yaml#ledger.claim ledger-field """On InnoDB, the demonstrated CHECK error leaves bob's earlier credit in A's transaction; explicit ROLLBACK then discards both balances' changes.""" M11 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02110 current docs/public/ledger.jsonl:2 scenarios/mysql/01-basics/atomicity.yaml#ledger.sessions ledger-field "[""A"",""B""]" M11 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02111 current docs/public/ledger.jsonl:2 scenarios/mysql/01-basics/atomicity.yaml#ledger.errors ledger-field "[""3819""]" M11 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02112 current docs/public/llms-full.txt:42 scenarios/mysql/01-basics/atomicity.yaml#llms.section.lines[42..100] llms-mirror Complete attributed section, lines 42-100; metadata and Transcript mirror for this exact schedule, source-field claims inventoried separately M11 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated mirror, same support as its exact Transcript and source fields Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02113 current docs/mysql/01-basics/parts/autocommit-visibility.md:1 scenarios/mysql/01-basics/autocommit-visibility.yaml#Transcript.lines[1..68] generated-mirror Complete SQL/status/results, narrator paragraphs, timeline labels and verification footer, lines 1-68; claims are the exact source-field occurrences inventoried separately M12 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Demonstrated schedule mirror, not independent all-schedule evidence Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02114 current docs/public/ledger.jsonl:3 scenarios/mysql/01-basics/autocommit-visibility.yaml#ledger.scenario ledger-field """mysql/01-basics/autocommit-visibility.yaml""" M12 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02115 current docs/public/ledger.jsonl:3 scenarios/mysql/01-basics/autocommit-visibility.yaml#ledger.engine ledger-field """mysql""" M12 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02116 current docs/public/ledger.jsonl:3 scenarios/mysql/01-basics/autocommit-visibility.yaml#ledger.product ledger-field """MySQL""" M12 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02117 current docs/public/ledger.jsonl:3 scenarios/mysql/01-basics/autocommit-visibility.yaml#ledger.version ledger-field """8.4.11""" M12 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02118 current docs/public/ledger.jsonl:3 scenarios/mysql/01-basics/autocommit-visibility.yaml#ledger.claim ledger-field """With autocommit=1 on InnoDB, A's successful standalone UPDATE is visible to B's later standalone SELECT. B excludes A's explicit-transaction UPDATE until COMMIT; a pre-existing REPEATABLE READ snapshot need not refresh.""" M12 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02119 current docs/public/ledger.jsonl:3 scenarios/mysql/01-basics/autocommit-visibility.yaml#ledger.sessions ledger-field "[""A"",""B""]" M12 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02120 current docs/public/ledger.jsonl:3 scenarios/mysql/01-basics/autocommit-visibility.yaml#ledger.errors ledger-field [] M12 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02121 current docs/public/llms-full.txt:101 scenarios/mysql/01-basics/autocommit-visibility.yaml#llms.section.lines[101..172] llms-mirror Complete attributed section, lines 101-172; metadata and Transcript mirror for this exact schedule, source-field claims inventoried separately M12 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated mirror, same support as its exact Transcript and source fields Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02122 current docs/mysql/01-basics/parts/savepoint-nesting.md:1 scenarios/mysql/01-basics/savepoint-nesting.yaml#Transcript.lines[1..56] generated-mirror Complete SQL/status/results, narrator paragraphs, timeline labels and verification footer, lines 1-56; claims are the exact source-field occurrences inventoried separately M13 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Demonstrated schedule mirror, not independent all-schedule evidence Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02123 current docs/public/ledger.jsonl:4 scenarios/mysql/01-basics/savepoint-nesting.yaml#ledger.scenario ledger-field """mysql/01-basics/savepoint-nesting.yaml""" M13 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02124 current docs/public/ledger.jsonl:4 scenarios/mysql/01-basics/savepoint-nesting.yaml#ledger.engine ledger-field """mysql""" M13 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02125 current docs/public/ledger.jsonl:4 scenarios/mysql/01-basics/savepoint-nesting.yaml#ledger.product ledger-field """MySQL""" M13 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02126 current docs/public/ledger.jsonl:4 scenarios/mysql/01-basics/savepoint-nesting.yaml#ledger.version ledger-field """8.4.11""" M13 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02127 current docs/public/ledger.jsonl:4 scenarios/mysql/01-basics/savepoint-nesting.yaml#ledger.claim ledger-field """Rolling back to an outer savepoint discards inner savepoints along with their work; RELEASE keeps the changes but forfeits the rollback point.""" M13 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02128 current docs/public/ledger.jsonl:4 scenarios/mysql/01-basics/savepoint-nesting.yaml#ledger.sessions ledger-field "[""A""]" M13 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02129 current docs/public/ledger.jsonl:4 scenarios/mysql/01-basics/savepoint-nesting.yaml#ledger.errors ledger-field "[""1305""]" M13 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02130 current docs/public/llms-full.txt:173 scenarios/mysql/01-basics/savepoint-nesting.yaml#llms.section.lines[173..232] llms-mirror Complete attributed section, lines 173-232; metadata and Transcript mirror for this exact schedule, source-field claims inventoried separately M13 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated mirror, same support as its exact Transcript and source fields Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02131 current docs/mysql/01-basics/parts/savepoint-recovery.md:1 scenarios/mysql/01-basics/savepoint-recovery.yaml#Transcript.lines[1..52] generated-mirror Complete SQL/status/results, narrator paragraphs, timeline labels and verification footer, lines 1-52; claims are the exact source-field occurrences inventoried separately M14 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Demonstrated schedule mirror, not independent all-schedule evidence Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02132 current docs/public/ledger.jsonl:5 scenarios/mysql/01-basics/savepoint-recovery.yaml#ledger.scenario ledger-field """mysql/01-basics/savepoint-recovery.yaml""" M14 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02133 current docs/public/ledger.jsonl:5 scenarios/mysql/01-basics/savepoint-recovery.yaml#ledger.engine ledger-field """mysql""" M14 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02134 current docs/public/ledger.jsonl:5 scenarios/mysql/01-basics/savepoint-recovery.yaml#ledger.product ledger-field """MySQL""" M14 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02135 current docs/public/ledger.jsonl:5 scenarios/mysql/01-basics/savepoint-recovery.yaml#ledger.version ledger-field """8.4.11""" M14 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02136 current docs/public/ledger.jsonl:5 scenarios/mysql/01-basics/savepoint-recovery.yaml#ledger.claim ledger-field """In this InnoDB INSERT branch, ROLLBACK TO SAVEPOINT removes the successful branch INSERT after a 1062 error, preserves the earlier INSERT, and allows the replacement branch to commit.""" M14 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02137 current docs/public/ledger.jsonl:5 scenarios/mysql/01-basics/savepoint-recovery.yaml#ledger.sessions ledger-field "[""A""]" M14 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02138 current docs/public/ledger.jsonl:5 scenarios/mysql/01-basics/savepoint-recovery.yaml#ledger.errors ledger-field "[""1062""]" M14 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02139 current docs/public/llms-full.txt:233 scenarios/mysql/01-basics/savepoint-recovery.yaml#llms.section.lines[233..288] llms-mirror Complete attributed section, lines 233-288; metadata and Transcript mirror for this exact schedule, source-field claims inventoried separately M14 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated mirror, same support as its exact Transcript and source fields Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02140 current docs/mysql/02-isolation/parts/circular-information-flow.md:1 scenarios/mysql/02-isolation/circular-information-flow.yaml#Transcript.lines[1..106] generated-mirror Complete SQL/status/results, narrator paragraphs, timeline labels and verification footer, lines 1-106; claims are the exact source-field occurrences inventoried separately M15 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Demonstrated schedule mirror, not independent all-schedule evidence Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02141 current docs/public/ledger.jsonl:6 scenarios/mysql/02-isolation/circular-information-flow.yaml#ledger.scenario ledger-field """mysql/02-isolation/circular-information-flow.yaml""" M15 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02142 current docs/public/ledger.jsonl:6 scenarios/mysql/02-isolation/circular-information-flow.yaml#ledger.engine ledger-field """mysql""" M15 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02143 current docs/public/ledger.jsonl:6 scenarios/mysql/02-isolation/circular-information-flow.yaml#ledger.product ledger-field """MySQL""" M15 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02144 current docs/public/ledger.jsonl:6 scenarios/mysql/02-isolation/circular-information-flow.yaml#ledger.version ledger-field """8.4.11""" M15 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02145 current docs/public/ledger.jsonl:6 scenarios/mysql/02-isolation/circular-information-flow.yaml#ledger.claim ledger-field """At READ UNCOMMITTED two concurrent transactions can each read the other's uncommitted write (Adya's G1c, \""circular information flow\""); an exchange no serial order can explain. The repeated READ COMMITTED schedule excludes those dirty cross-reads, but its two old reads do not prove serializability.""" M15 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02146 current docs/public/ledger.jsonl:6 scenarios/mysql/02-isolation/circular-information-flow.yaml#ledger.sessions ledger-field "[""A"",""B""]" M15 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02147 current docs/public/ledger.jsonl:6 scenarios/mysql/02-isolation/circular-information-flow.yaml#ledger.errors ledger-field [] M15 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02148 current docs/public/ledger.jsonl:6 scenarios/mysql/02-isolation/circular-information-flow.yaml#ledger.anomaly ledger-field """G1c""" M15 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02149 current docs/public/llms-full.txt:289 scenarios/mysql/02-isolation/circular-information-flow.yaml#llms.section.lines[289..398] llms-mirror Complete attributed section, lines 289-398; metadata and Transcript mirror for this exact schedule, source-field claims inventoried separately M15 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated mirror, same support as its exact Transcript and source fields Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02150 current docs/mysql/02-isolation/parts/current-reads.md:1 scenarios/mysql/02-isolation/current-reads.yaml#Transcript.lines[1..98] generated-mirror Complete SQL/status/results, narrator paragraphs, timeline labels and verification footer, lines 1-98; claims are the exact source-field occurrences inventoried separately M16 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Demonstrated schedule mirror, not independent all-schedule evidence Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02151 current docs/public/ledger.jsonl:7 scenarios/mysql/02-isolation/current-reads.yaml#ledger.scenario ledger-field """mysql/02-isolation/current-reads.yaml""" M16 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02152 current docs/public/ledger.jsonl:7 scenarios/mysql/02-isolation/current-reads.yaml#ledger.engine ledger-field """mysql""" M16 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02153 current docs/public/ledger.jsonl:7 scenarios/mysql/02-isolation/current-reads.yaml#ledger.product ledger-field """MySQL""" M16 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02154 current docs/public/ledger.jsonl:7 scenarios/mysql/02-isolation/current-reads.yaml#ledger.version ledger-field """8.4.11""" M16 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02155 current docs/public/ledger.jsonl:7 scenarios/mysql/02-isolation/current-reads.yaml#ledger.claim ledger-field """In this InnoDB REPEATABLE READ schedule, A's UPDATE computes from B's committed 150, not its snapshot's 100, and A reads its own result 200. In the second attempt A waits for B's commit of 300 and produces 350.""" M16 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02156 current docs/public/ledger.jsonl:7 scenarios/mysql/02-isolation/current-reads.yaml#ledger.sessions ledger-field "[""A"",""B""]" M16 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02157 current docs/public/ledger.jsonl:7 scenarios/mysql/02-isolation/current-reads.yaml#ledger.errors ledger-field [] M16 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02158 current docs/public/llms-full.txt:399 scenarios/mysql/02-isolation/current-reads.yaml#llms.section.lines[399..500] llms-mirror Complete attributed section, lines 399-500; metadata and Transcript mirror for this exact schedule, source-field claims inventoried separately M16 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated mirror, same support as its exact Transcript and source fields Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02159 current docs/mysql/02-isolation/parts/dirty-read.md:1 scenarios/mysql/02-isolation/dirty-read.yaml#Transcript.lines[1..56] generated-mirror Complete SQL/status/results, narrator paragraphs, timeline labels and verification footer, lines 1-56; claims are the exact source-field occurrences inventoried separately M17 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Demonstrated schedule mirror, not independent all-schedule evidence Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02160 current docs/public/ledger.jsonl:8 scenarios/mysql/02-isolation/dirty-read.yaml#ledger.scenario ledger-field """mysql/02-isolation/dirty-read.yaml""" M17 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02161 current docs/public/ledger.jsonl:8 scenarios/mysql/02-isolation/dirty-read.yaml#ledger.engine ledger-field """mysql""" M17 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02162 current docs/public/ledger.jsonl:8 scenarios/mysql/02-isolation/dirty-read.yaml#ledger.product ledger-field """MySQL""" M17 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02163 current docs/public/ledger.jsonl:8 scenarios/mysql/02-isolation/dirty-read.yaml#ledger.version ledger-field """8.4.11""" M17 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02164 current docs/public/ledger.jsonl:8 scenarios/mysql/02-isolation/dirty-read.yaml#ledger.claim ledger-field """At READ UNCOMMITTED, MySQL serves other transactions' uncommitted changes including the asserted 999 that A later rolls back. The value existed uncommitted, but never became part of committed history.""" M17 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02165 current docs/public/ledger.jsonl:8 scenarios/mysql/02-isolation/dirty-read.yaml#ledger.sessions ledger-field "[""A"",""B""]" M17 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02166 current docs/public/ledger.jsonl:8 scenarios/mysql/02-isolation/dirty-read.yaml#ledger.errors ledger-field [] M17 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02167 current docs/public/ledger.jsonl:8 scenarios/mysql/02-isolation/dirty-read.yaml#ledger.anomaly ledger-field """G1a""" M17 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02168 current docs/public/ledger.jsonl:8 scenarios/mysql/02-isolation/dirty-read.yaml#ledger.isolation ledger-field """READ UNCOMMITTED""" M17 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02169 current docs/public/llms-full.txt:501 scenarios/mysql/02-isolation/dirty-read.yaml#llms.section.lines[501..560] llms-mirror Complete attributed section, lines 501-560; metadata and Transcript mirror for this exact schedule, source-field claims inventoried separately M17 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated mirror, same support as its exact Transcript and source fields Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02170 current docs/mysql/02-isolation/parts/dirty-write.md:1 scenarios/mysql/02-isolation/dirty-write.yaml#Transcript.lines[1..62] generated-mirror Complete SQL/status/results, narrator paragraphs, timeline labels and verification footer, lines 1-62; claims are the exact source-field occurrences inventoried separately M18 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Demonstrated schedule mirror, not independent all-schedule evidence Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02171 current docs/public/ledger.jsonl:9 scenarios/mysql/02-isolation/dirty-write.yaml#ledger.scenario ledger-field """mysql/02-isolation/dirty-write.yaml""" M18 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02172 current docs/public/ledger.jsonl:9 scenarios/mysql/02-isolation/dirty-write.yaml#ledger.engine ledger-field """mysql""" M18 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02173 current docs/public/ledger.jsonl:9 scenarios/mysql/02-isolation/dirty-write.yaml#ledger.product ledger-field """MySQL""" M18 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02174 current docs/public/ledger.jsonl:9 scenarios/mysql/02-isolation/dirty-write.yaml#ledger.version ledger-field """8.4.11""" M18 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02175 current docs/public/ledger.jsonl:9 scenarios/mysql/02-isolation/dirty-write.yaml#ledger.claim ledger-field """In this InnoDB READ UNCOMMITTED schedule, B's UPDATE of A's uncommitted row waits until A commits. Both of B's later prices are asserted after B commits. All-level dirty-write exclusion needs the row-lock contract.""" M18 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02176 current docs/public/ledger.jsonl:9 scenarios/mysql/02-isolation/dirty-write.yaml#ledger.sessions ledger-field "[""A"",""B""]" M18 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02177 current docs/public/ledger.jsonl:9 scenarios/mysql/02-isolation/dirty-write.yaml#ledger.errors ledger-field [] M18 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02178 current docs/public/ledger.jsonl:9 scenarios/mysql/02-isolation/dirty-write.yaml#ledger.anomaly ledger-field """G0""" M18 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02179 current docs/public/ledger.jsonl:9 scenarios/mysql/02-isolation/dirty-write.yaml#ledger.isolation ledger-field """READ UNCOMMITTED""" M18 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02180 current docs/public/llms-full.txt:561 scenarios/mysql/02-isolation/dirty-write.yaml#llms.section.lines[561..626] llms-mirror Complete attributed section, lines 561-626; metadata and Transcript mirror for this exact schedule, source-field claims inventoried separately M18 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated mirror, same support as its exact Transcript and source fields Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02181 current docs/mysql/02-isolation/parts/intermediate-read.md:1 scenarios/mysql/02-isolation/intermediate-read.yaml#Transcript.lines[1..76] generated-mirror Complete SQL/status/results, narrator paragraphs, timeline labels and verification footer, lines 1-76; claims are the exact source-field occurrences inventoried separately M19 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Demonstrated schedule mirror, not independent all-schedule evidence Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02182 current docs/public/ledger.jsonl:10 scenarios/mysql/02-isolation/intermediate-read.yaml#ledger.scenario ledger-field """mysql/02-isolation/intermediate-read.yaml""" M19 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02183 current docs/public/ledger.jsonl:10 scenarios/mysql/02-isolation/intermediate-read.yaml#ledger.engine ledger-field """mysql""" M19 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02184 current docs/public/ledger.jsonl:10 scenarios/mysql/02-isolation/intermediate-read.yaml#ledger.product ledger-field """MySQL""" M19 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02185 current docs/public/ledger.jsonl:10 scenarios/mysql/02-isolation/intermediate-read.yaml#ledger.version ledger-field """8.4.11""" M19 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02186 current docs/public/ledger.jsonl:10 scenarios/mysql/02-isolation/intermediate-read.yaml#ledger.claim ledger-field """At READ UNCOMMITTED a reader can observe an intermediate value the writer later overwrites before committing (Adya's G1b, \""intermediate read\""); a number absent from committed history. In the repeated READ COMMITTED schedule, B reads 110 while A's draft 555 is uncommitted.""" M19 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02187 current docs/public/ledger.jsonl:10 scenarios/mysql/02-isolation/intermediate-read.yaml#ledger.sessions ledger-field "[""A"",""B""]" M19 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02188 current docs/public/ledger.jsonl:10 scenarios/mysql/02-isolation/intermediate-read.yaml#ledger.errors ledger-field [] M19 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02189 current docs/public/ledger.jsonl:10 scenarios/mysql/02-isolation/intermediate-read.yaml#ledger.anomaly ledger-field """G1b""" M19 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02190 current docs/public/llms-full.txt:627 scenarios/mysql/02-isolation/intermediate-read.yaml#llms.section.lines[627..706] llms-mirror Complete attributed section, lines 627-706; metadata and Transcript mirror for this exact schedule, source-field claims inventoried separately M19 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated mirror, same support as its exact Transcript and source fields Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02191 current docs/mysql/02-isolation/parts/lost-update-read-committed.md:1 scenarios/mysql/02-isolation/lost-update-read-committed.yaml#Transcript.lines[1..65] generated-mirror Complete SQL/status/results, narrator paragraphs, timeline labels and verification footer, lines 1-65; claims are the exact source-field occurrences inventoried separately M20 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Demonstrated schedule mirror, not independent all-schedule evidence Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02192 current docs/public/ledger.jsonl:11 scenarios/mysql/02-isolation/lost-update-read-committed.yaml#ledger.scenario ledger-field """mysql/02-isolation/lost-update-read-committed.yaml""" M20 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02193 current docs/public/ledger.jsonl:11 scenarios/mysql/02-isolation/lost-update-read-committed.yaml#ledger.engine ledger-field """mysql""" M20 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02194 current docs/public/ledger.jsonl:11 scenarios/mysql/02-isolation/lost-update-read-committed.yaml#ledger.product ledger-field """MySQL""" M20 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02195 current docs/public/ledger.jsonl:11 scenarios/mysql/02-isolation/lost-update-read-committed.yaml#ledger.version ledger-field """8.4.11""" M20 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02196 current docs/public/ledger.jsonl:11 scenarios/mysql/02-isolation/lost-update-read-committed.yaml#ledger.claim ledger-field """Two read-modify-write transactions at READ COMMITTED can silently overwrite each other: two deposits of 10 grow the balance by only 10.""" M20 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02197 current docs/public/ledger.jsonl:11 scenarios/mysql/02-isolation/lost-update-read-committed.yaml#ledger.sessions ledger-field "[""A"",""B""]" M20 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02198 current docs/public/ledger.jsonl:11 scenarios/mysql/02-isolation/lost-update-read-committed.yaml#ledger.errors ledger-field [] M20 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02199 current docs/public/ledger.jsonl:11 scenarios/mysql/02-isolation/lost-update-read-committed.yaml#ledger.anomaly ledger-field """P4""" M20 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02200 current docs/public/ledger.jsonl:11 scenarios/mysql/02-isolation/lost-update-read-committed.yaml#ledger.isolation ledger-field """READ COMMITTED""" M20 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02201 current docs/public/llms-full.txt:707 scenarios/mysql/02-isolation/lost-update-read-committed.yaml#llms.section.lines[707..775] llms-mirror Complete attributed section, lines 707-775; metadata and Transcript mirror for this exact schedule, source-field claims inventoried separately M20 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated mirror, same support as its exact Transcript and source fields Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02202 current docs/mysql/02-isolation/parts/lost-update-repeatable-read.md:1 scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml#Transcript.lines[1..65] generated-mirror Complete SQL/status/results, narrator paragraphs, timeline labels and verification footer, lines 1-65; claims are the exact source-field occurrences inventoried separately M21 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Demonstrated schedule mirror, not independent all-schedule evidence Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02203 current docs/public/ledger.jsonl:12 scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml#ledger.scenario ledger-field """mysql/02-isolation/lost-update-repeatable-read.yaml""" M21 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02204 current docs/public/ledger.jsonl:12 scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml#ledger.engine ledger-field """mysql""" M21 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02205 current docs/public/ledger.jsonl:12 scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml#ledger.product ledger-field """MySQL""" M21 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02206 current docs/public/ledger.jsonl:12 scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml#ledger.version ledger-field """8.4.11""" M21 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02207 current docs/public/ledger.jsonl:12 scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml#ledger.claim ledger-field """In this InnoDB REPEATABLE READ schedule, both transactions read 100 and commit writes of that value plus 10 without error; the final balance is 110, not 120. A stale literal write is not rejected merely for staleness.""" M21 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02208 current docs/public/ledger.jsonl:12 scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml#ledger.sessions ledger-field "[""A"",""B""]" M21 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02209 current docs/public/ledger.jsonl:12 scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml#ledger.errors ledger-field [] M21 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02210 current docs/public/ledger.jsonl:12 scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml#ledger.anomaly ledger-field """P4""" M21 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02211 current docs/public/ledger.jsonl:12 scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml#ledger.isolation ledger-field """REPEATABLE READ""" M21 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02212 current docs/public/llms-full.txt:776 scenarios/mysql/02-isolation/lost-update-repeatable-read.yaml#llms.section.lines[776..844] llms-mirror Complete attributed section, lines 776-844; metadata and Transcript mirror for this exact schedule, source-field claims inventoried separately M21 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated mirror, same support as its exact Transcript and source fields Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02213 current docs/mysql/02-isolation/parts/non-repeatable-read.md:1 scenarios/mysql/02-isolation/non-repeatable-read.yaml#Transcript.lines[1..64] generated-mirror Complete SQL/status/results, narrator paragraphs, timeline labels and verification footer, lines 1-64; claims are the exact source-field occurrences inventoried separately M22 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Demonstrated schedule mirror, not independent all-schedule evidence Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02214 current docs/public/ledger.jsonl:13 scenarios/mysql/02-isolation/non-repeatable-read.yaml#ledger.scenario ledger-field """mysql/02-isolation/non-repeatable-read.yaml""" M22 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02215 current docs/public/ledger.jsonl:13 scenarios/mysql/02-isolation/non-repeatable-read.yaml#ledger.engine ledger-field """mysql""" M22 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02216 current docs/public/ledger.jsonl:13 scenarios/mysql/02-isolation/non-repeatable-read.yaml#ledger.product ledger-field """MySQL""" M22 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02217 current docs/public/ledger.jsonl:13 scenarios/mysql/02-isolation/non-repeatable-read.yaml#ledger.version ledger-field """8.4.11""" M22 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02218 current docs/public/ledger.jsonl:13 scenarios/mysql/02-isolation/non-repeatable-read.yaml#ledger.claim ledger-field """At READ COMMITTED, a transaction can read two different values for the same row; other transactions' commits become visible between its statements.""" M22 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02219 current docs/public/ledger.jsonl:13 scenarios/mysql/02-isolation/non-repeatable-read.yaml#ledger.sessions ledger-field "[""A"",""B""]" M22 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02220 current docs/public/ledger.jsonl:13 scenarios/mysql/02-isolation/non-repeatable-read.yaml#ledger.errors ledger-field [] M22 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02221 current docs/public/ledger.jsonl:13 scenarios/mysql/02-isolation/non-repeatable-read.yaml#ledger.anomaly ledger-field """P2""" M22 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02222 current docs/public/ledger.jsonl:13 scenarios/mysql/02-isolation/non-repeatable-read.yaml#ledger.isolation ledger-field """READ COMMITTED""" M22 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02223 current docs/public/llms-full.txt:845 scenarios/mysql/02-isolation/non-repeatable-read.yaml#llms.section.lines[845..912] llms-mirror Complete attributed section, lines 845-912; metadata and Transcript mirror for this exact schedule, source-field claims inventoried separately M22 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated mirror, same support as its exact Transcript and source fields Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02224 current docs/mysql/02-isolation/parts/observed-transaction-vanishes.md:1 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#Transcript.lines[1..109] generated-mirror Complete SQL/status/results, narrator paragraphs, timeline labels and verification footer, lines 1-109; claims are the exact source-field occurrences inventoried separately M23 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Demonstrated schedule mirror, not independent all-schedule evidence Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02225 current docs/public/ledger.jsonl:14 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#ledger.scenario ledger-field """mysql/02-isolation/observed-transaction-vanishes.yaml""" M23 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02226 current docs/public/ledger.jsonl:14 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#ledger.engine ledger-field """mysql""" M23 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02227 current docs/public/ledger.jsonl:14 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#ledger.product ledger-field """MySQL""" M23 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02228 current docs/public/ledger.jsonl:14 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#ledger.version ledger-field """8.4.11""" M23 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02229 current docs/public/ledger.jsonl:14 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#ledger.claim ledger-field """At READ UNCOMMITTED a reader can see a later transaction's uncommitted overwrite of one row while relying on the overwritten transaction's other row (Adya's OTV, \""observed transaction vanishes\""); the committed transaction is visible only in pieces in this schedule. The repeated READ COMMITTED SELECTs exclude A's draft and see both rows after commit; separate statements do not have one shared snapshot.""" M23 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02230 current docs/public/ledger.jsonl:14 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#ledger.sessions ledger-field "[""A"",""B"",""C""]" M23 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02231 current docs/public/ledger.jsonl:14 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#ledger.errors ledger-field [] M23 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02232 current docs/public/ledger.jsonl:14 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#ledger.anomaly ledger-field """OTV""" M23 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02233 current docs/public/llms-full.txt:913 scenarios/mysql/02-isolation/observed-transaction-vanishes.yaml#llms.section.lines[913..1025] llms-mirror Complete attributed section, lines 913-1025; metadata and Transcript mirror for this exact schedule, source-field claims inventoried separately M23 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated mirror, same support as its exact Transcript and source fields Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02234 current docs/mysql/02-isolation/parts/phantom-read.md:1 scenarios/mysql/02-isolation/phantom-read.yaml#Transcript.lines[1..43] generated-mirror Complete SQL/status/results, narrator paragraphs, timeline labels and verification footer, lines 1-43; claims are the exact source-field occurrences inventoried separately M24 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Demonstrated schedule mirror, not independent all-schedule evidence Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02235 current docs/public/ledger.jsonl:15 scenarios/mysql/02-isolation/phantom-read.yaml#ledger.scenario ledger-field """mysql/02-isolation/phantom-read.yaml""" M24 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02236 current docs/public/ledger.jsonl:15 scenarios/mysql/02-isolation/phantom-read.yaml#ledger.engine ledger-field """mysql""" M24 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02237 current docs/public/ledger.jsonl:15 scenarios/mysql/02-isolation/phantom-read.yaml#ledger.product ledger-field """MySQL""" M24 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02238 current docs/public/ledger.jsonl:15 scenarios/mysql/02-isolation/phantom-read.yaml#ledger.version ledger-field """8.4.11""" M24 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02239 current docs/public/ledger.jsonl:15 scenarios/mysql/02-isolation/phantom-read.yaml#ledger.claim ledger-field """At READ COMMITTED, re-running the same range query inside one transaction can return rows that weren't there before; phantoms.""" M24 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02240 current docs/public/ledger.jsonl:15 scenarios/mysql/02-isolation/phantom-read.yaml#ledger.sessions ledger-field "[""A"",""B""]" M24 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02241 current docs/public/ledger.jsonl:15 scenarios/mysql/02-isolation/phantom-read.yaml#ledger.errors ledger-field [] M24 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02242 current docs/public/ledger.jsonl:15 scenarios/mysql/02-isolation/phantom-read.yaml#ledger.anomaly ledger-field """PMP""" M24 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02243 current docs/public/ledger.jsonl:15 scenarios/mysql/02-isolation/phantom-read.yaml#ledger.isolation ledger-field """READ COMMITTED""" M24 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02244 current docs/public/llms-full.txt:1026 scenarios/mysql/02-isolation/phantom-read.yaml#llms.section.lines[1026..1072] llms-mirror Complete attributed section, lines 1026-1072; metadata and Transcript mirror for this exact schedule, source-field claims inventoried separately M24 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated mirror, same support as its exact Transcript and source fields Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02245 current docs/mysql/02-isolation/parts/read-skew.md:1 scenarios/mysql/02-isolation/read-skew.yaml#Transcript.lines[1..85] generated-mirror Complete SQL/status/results, narrator paragraphs, timeline labels and verification footer, lines 1-85; claims are the exact source-field occurrences inventoried separately M25 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Demonstrated schedule mirror, not independent all-schedule evidence Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02246 current docs/public/ledger.jsonl:16 scenarios/mysql/02-isolation/read-skew.yaml#ledger.scenario ledger-field """mysql/02-isolation/read-skew.yaml""" M25 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02247 current docs/public/ledger.jsonl:16 scenarios/mysql/02-isolation/read-skew.yaml#ledger.engine ledger-field """mysql""" M25 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02248 current docs/public/ledger.jsonl:16 scenarios/mysql/02-isolation/read-skew.yaml#ledger.product ledger-field """MySQL""" M25 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02249 current docs/public/ledger.jsonl:16 scenarios/mysql/02-isolation/read-skew.yaml#ledger.version ledger-field """8.4.11""" M25 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02250 current docs/public/ledger.jsonl:16 scenarios/mysql/02-isolation/read-skew.yaml#ledger.claim ledger-field """At READ COMMITTED, a transaction reading two rows around a concurrent transfer observes money that never existed (Adya's G-single, \""read skew\""); the repeated REPEATABLE READ schedule returns 25 and 75 from one snapshot, with no writes by the reader.""" M25 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02251 current docs/public/ledger.jsonl:16 scenarios/mysql/02-isolation/read-skew.yaml#ledger.sessions ledger-field "[""A"",""B""]" M25 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02252 current docs/public/ledger.jsonl:16 scenarios/mysql/02-isolation/read-skew.yaml#ledger.errors ledger-field [] M25 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02253 current docs/public/ledger.jsonl:16 scenarios/mysql/02-isolation/read-skew.yaml#ledger.anomaly ledger-field """G-single""" M25 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02254 current docs/public/llms-full.txt:1073 scenarios/mysql/02-isolation/read-skew.yaml#llms.section.lines[1073..1161] llms-mirror Complete attributed section, lines 1073-1161; metadata and Transcript mirror for this exact schedule, source-field claims inventoried separately M25 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated mirror, same support as its exact Transcript and source fields Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02255 current docs/mysql/02-isolation/parts/stable-snapshot.md:1 scenarios/mysql/02-isolation/stable-snapshot.yaml#Transcript.lines[1..76] generated-mirror Complete SQL/status/results, narrator paragraphs, timeline labels and verification footer, lines 1-76; claims are the exact source-field occurrences inventoried separately M26 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Demonstrated schedule mirror, not independent all-schedule evidence Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02256 current docs/public/ledger.jsonl:17 scenarios/mysql/02-isolation/stable-snapshot.yaml#ledger.scenario ledger-field """mysql/02-isolation/stable-snapshot.yaml""" M26 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02257 current docs/public/ledger.jsonl:17 scenarios/mysql/02-isolation/stable-snapshot.yaml#ledger.engine ledger-field """mysql""" M26 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02258 current docs/public/ledger.jsonl:17 scenarios/mysql/02-isolation/stable-snapshot.yaml#ledger.product ledger-field """MySQL""" M26 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02259 current docs/public/ledger.jsonl:17 scenarios/mysql/02-isolation/stable-snapshot.yaml#ledger.version ledger-field """8.4.11""" M26 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02260 current docs/public/ledger.jsonl:17 scenarios/mysql/02-isolation/stable-snapshot.yaml#ledger.claim ledger-field """In this InnoDB REPEATABLE READ schedule, the first consistent SELECT includes a commit after BEGIN. Later consistent SELECTs exclude B's later UPDATE and INSERT, include A's own UPDATE, and refresh after A commits.""" M26 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02261 current docs/public/ledger.jsonl:17 scenarios/mysql/02-isolation/stable-snapshot.yaml#ledger.sessions ledger-field "[""A"",""B""]" M26 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02262 current docs/public/ledger.jsonl:17 scenarios/mysql/02-isolation/stable-snapshot.yaml#ledger.errors ledger-field [] M26 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02263 current docs/public/ledger.jsonl:17 scenarios/mysql/02-isolation/stable-snapshot.yaml#ledger.anomaly ledger-field """P2""" M26 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02264 current docs/public/ledger.jsonl:17 scenarios/mysql/02-isolation/stable-snapshot.yaml#ledger.isolation ledger-field """REPEATABLE READ""" M26 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02265 current docs/public/llms-full.txt:1162 scenarios/mysql/02-isolation/stable-snapshot.yaml#llms.section.lines[1162..1241] llms-mirror Complete attributed section, lines 1162-1241; metadata and Transcript mirror for this exact schedule, source-field claims inventoried separately M26 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated mirror, same support as its exact Transcript and source fields Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02266 current docs/mysql/02-isolation/parts/update-recheck.md:1 scenarios/mysql/02-isolation/update-recheck.yaml#Transcript.lines[1..55] generated-mirror Complete SQL/status/results, narrator paragraphs, timeline labels and verification footer, lines 1-55; claims are the exact source-field occurrences inventoried separately M27 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Demonstrated schedule mirror, not independent all-schedule evidence Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02267 current docs/public/ledger.jsonl:18 scenarios/mysql/02-isolation/update-recheck.yaml#ledger.scenario ledger-field """mysql/02-isolation/update-recheck.yaml""" M27 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02268 current docs/public/ledger.jsonl:18 scenarios/mysql/02-isolation/update-recheck.yaml#ledger.engine ledger-field """mysql""" M27 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02269 current docs/public/ledger.jsonl:18 scenarios/mysql/02-isolation/update-recheck.yaml#ledger.product ledger-field """MySQL""" M27 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02270 current docs/public/ledger.jsonl:18 scenarios/mysql/02-isolation/update-recheck.yaml#ledger.version ledger-field """8.4.11""" M27 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02271 current docs/public/ledger.jsonl:18 scenarios/mysql/02-isolation/update-recheck.yaml#ledger.claim ledger-field """An UPDATE at READ COMMITTED that waited for a lock re-evaluates its WHERE clause against the new row version; rows that no longer match are silently skipped.""" M27 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02272 current docs/public/ledger.jsonl:18 scenarios/mysql/02-isolation/update-recheck.yaml#ledger.sessions ledger-field "[""A"",""B""]" M27 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02273 current docs/public/ledger.jsonl:18 scenarios/mysql/02-isolation/update-recheck.yaml#ledger.errors ledger-field [] M27 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02274 current docs/public/llms-full.txt:1242 scenarios/mysql/02-isolation/update-recheck.yaml#llms.section.lines[1242..1300] llms-mirror Complete attributed section, lines 1242-1300; metadata and Transcript mirror for this exact schedule, source-field claims inventoried separately M27 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated mirror, same support as its exact Transcript and source fields Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02275 current docs/mysql/02-isolation/parts/write-predicate-skew.md:1 scenarios/mysql/02-isolation/write-predicate-skew.yaml#Transcript.lines[1..57] generated-mirror Complete SQL/status/results, narrator paragraphs, timeline labels and verification footer, lines 1-57; claims are the exact source-field occurrences inventoried separately M28 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Demonstrated schedule mirror, not independent all-schedule evidence Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02276 current docs/public/ledger.jsonl:19 scenarios/mysql/02-isolation/write-predicate-skew.yaml#ledger.scenario ledger-field """mysql/02-isolation/write-predicate-skew.yaml""" M28 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02277 current docs/public/ledger.jsonl:19 scenarios/mysql/02-isolation/write-predicate-skew.yaml#ledger.engine ledger-field """mysql""" M28 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02278 current docs/public/ledger.jsonl:19 scenarios/mysql/02-isolation/write-predicate-skew.yaml#ledger.product ledger-field """MySQL""" M28 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02279 current docs/public/ledger.jsonl:19 scenarios/mysql/02-isolation/write-predicate-skew.yaml#ledger.version ledger-field """8.4.11""" M28 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02280 current docs/public/ledger.jsonl:19 scenarios/mysql/02-isolation/write-predicate-skew.yaml#ledger.claim ledger-field """In this InnoDB REPEATABLE READ schedule, A's DELETE of balance=20 finds no current matching row after B commits 15/25, while A's consistent SELECT still returns snapshot balance 20. The DELETE affects zero rows.""" M28 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02281 current docs/public/ledger.jsonl:19 scenarios/mysql/02-isolation/write-predicate-skew.yaml#ledger.sessions ledger-field "[""A"",""B""]" M28 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02282 current docs/public/ledger.jsonl:19 scenarios/mysql/02-isolation/write-predicate-skew.yaml#ledger.errors ledger-field [] M28 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02283 current docs/public/llms-full.txt:1301 scenarios/mysql/02-isolation/write-predicate-skew.yaml#llms.section.lines[1301..1361] llms-mirror Complete attributed section, lines 1301-1361; metadata and Transcript mirror for this exact schedule, source-field claims inventoried separately M28 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated mirror, same support as its exact Transcript and source fields Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02284 current docs/mysql/02-isolation/parts/write-skew-rr.md:1 scenarios/mysql/02-isolation/write-skew-rr.yaml#Transcript.lines[1..67] generated-mirror Complete SQL/status/results, narrator paragraphs, timeline labels and verification footer, lines 1-67; claims are the exact source-field occurrences inventoried separately M29 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Demonstrated schedule mirror, not independent all-schedule evidence Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02285 current docs/public/ledger.jsonl:20 scenarios/mysql/02-isolation/write-skew-rr.yaml#ledger.scenario ledger-field """mysql/02-isolation/write-skew-rr.yaml""" M29 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02286 current docs/public/ledger.jsonl:20 scenarios/mysql/02-isolation/write-skew-rr.yaml#ledger.engine ledger-field """mysql""" M29 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02287 current docs/public/ledger.jsonl:20 scenarios/mysql/02-isolation/write-skew-rr.yaml#ledger.product ledger-field """MySQL""" M29 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02288 current docs/public/ledger.jsonl:20 scenarios/mysql/02-isolation/write-skew-rr.yaml#ledger.version ledger-field """8.4.11""" M29 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02289 current docs/public/ledger.jsonl:20 scenarios/mysql/02-isolation/write-skew-rr.yaml#ledger.claim ledger-field """Two REPEATABLE READ transactions can each validate an invariant against their snapshots, write to different rows, and both commit; leaving the invariant broken. This is write skew.""" M29 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02290 current docs/public/ledger.jsonl:20 scenarios/mysql/02-isolation/write-skew-rr.yaml#ledger.sessions ledger-field "[""A"",""B""]" M29 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02291 current docs/public/ledger.jsonl:20 scenarios/mysql/02-isolation/write-skew-rr.yaml#ledger.errors ledger-field [] M29 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02292 current docs/public/ledger.jsonl:20 scenarios/mysql/02-isolation/write-skew-rr.yaml#ledger.anomaly ledger-field """G2-item""" M29 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02293 current docs/public/ledger.jsonl:20 scenarios/mysql/02-isolation/write-skew-rr.yaml#ledger.isolation ledger-field """REPEATABLE READ""" M29 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02294 current docs/public/llms-full.txt:1362 scenarios/mysql/02-isolation/write-skew-rr.yaml#llms.section.lines[1362..1432] llms-mirror Complete attributed section, lines 1362-1432; metadata and Transcript mirror for this exact schedule, source-field claims inventoried separately M29 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated mirror, same support as its exact Transcript and source fields Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02295 current docs/mysql/02-isolation/parts/write-skew-serializable.md:1 scenarios/mysql/02-isolation/write-skew-serializable.yaml#Transcript.lines[1..155] generated-mirror Complete SQL/status/results, narrator paragraphs, timeline labels and verification footer, lines 1-155; claims are the exact source-field occurrences inventoried separately M30 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Demonstrated schedule mirror, not independent all-schedule evidence Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02296 current docs/public/ledger.jsonl:21 scenarios/mysql/02-isolation/write-skew-serializable.yaml#ledger.scenario ledger-field """mysql/02-isolation/write-skew-serializable.yaml""" M30 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02297 current docs/public/ledger.jsonl:21 scenarios/mysql/02-isolation/write-skew-serializable.yaml#ledger.engine ledger-field """mysql""" M30 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02298 current docs/public/ledger.jsonl:21 scenarios/mysql/02-isolation/write-skew-serializable.yaml#ledger.product ledger-field """MySQL""" M30 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02299 current docs/public/ledger.jsonl:21 scenarios/mysql/02-isolation/write-skew-serializable.yaml#ledger.version ledger-field """8.4.11""" M30 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02300 current docs/public/ledger.jsonl:21 scenarios/mysql/02-isolation/write-skew-serializable.yaml#ledger.claim ledger-field """In these explicit InnoDB SERIALIZABLE transactions with deadlock detection enabled, the count SELECTs take shared locks. This schedule rejects B's UPDATE with 1213, A commits, and a fresh B attempt sees one doctor and declines to leave. Other schedules need not select B as victim.""" M30 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02301 current docs/public/ledger.jsonl:21 scenarios/mysql/02-isolation/write-skew-serializable.yaml#ledger.sessions ledger-field "[""A"",""B""]" M30 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02302 current docs/public/ledger.jsonl:21 scenarios/mysql/02-isolation/write-skew-serializable.yaml#ledger.errors ledger-field "[""1213""]" M30 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02303 current docs/public/ledger.jsonl:21 scenarios/mysql/02-isolation/write-skew-serializable.yaml#ledger.anomaly ledger-field """G2-item""" M30 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02304 current docs/public/ledger.jsonl:21 scenarios/mysql/02-isolation/write-skew-serializable.yaml#ledger.isolation ledger-field """SERIALIZABLE""" M30 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated Scenario metadata mirror; error set does not imply every error is exercised Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee C02305 current docs/public/llms-full.txt:1433 scenarios/mysql/02-isolation/write-skew-serializable.yaml#llms.section.lines[1433..1591] llms-mirror Complete attributed section, lines 1433-1591; metadata and Transcript mirror for this exact schedule, source-field claims inventoried separately M30 MySQL 8.4.11 observed schedules, InnoDB table DML, initial autocommit=1 and REPEATABLE READ unless SQL overrides it; MySQL 8.4 manual contracts. No crash/network/external-effect executions. Own writes remain visible. Scope narrows further in the inventoried statement or catalog cell. Generated mirror, same support as its exact Transcript and source fields Supported within stated schedule/contract/derivation scope; editorial or generated fields carry no additional guarantee