From 7a0a21753c09646fb70054fed728aa3fb1bd8438 Mon Sep 17 00:00:00 2001 From: Yasuo Honda Date: Fri, 28 Aug 2026 10:53:55 +0900 Subject: [PATCH 1/2] transaction-isolation-levels: clarify ambiguous "the transaction statement" wording MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit "The transaction statement" reads as if it names a specific category of statement, when the intended meaning (confirmed against the Chinese source, docs-cn's "对于本事务而言，事务语句可以看到之前的语句 做出的修改") is that a statement within a transaction can see the effects of earlier statements in that SAME transaction, contrasted with not seeing other transactions' uncommitted or concurrent changes. Rewords to make the "within its own transaction" contrast explicit. --- transaction-isolation-levels.md | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/transaction-isolation-levels.md b/transaction-isolation-levels.md index e24efb41e955f..a6b52467a8191 100644 --- a/transaction-isolation-levels.md +++ b/transaction-isolation-levels.md @@ -36,7 +36,7 @@ TiDB implements Snapshot Isolation (SI) consistency, which it advertises as `REP ## Repeatable Read isolation level -The Repeatable Read isolation level only sees data committed before the transaction begins, and it never sees either uncommitted data or changes committed during transaction execution by concurrent transactions. However, the transaction statement does see the effects of previous updates executed within its own transaction, even though they are not yet committed. +The Repeatable Read isolation level only sees data committed before the transaction begins, and it never sees either uncommitted data or changes committed during transaction execution by concurrent transactions. However, within its own transaction, a statement does see the effects of updates made by previous statements in that transaction, even though those updates are not yet committed. For transactions running on different nodes, the start and commit order depends on the order that the timestamp is obtained from PD. From 288e32b38066b68ba5815e480d322a72074e2732 Mon Sep 17 00:00:00 2001 From: Yasuo Honda Date: Fri, 28 Aug 2026 11:08:03 +0900 Subject: [PATCH 2/2] transaction-isolation-levels: fix subject-verb agreement error MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit "though they sharing the same name" is not a grammatical clause (a gerund cannot follow the subject "they" as the main verb). Fixed to "though they share the same name", and added the missing article before "ANSI Repeatable Read isolation level" for consistency with its other mention later in the same paragraph. Verified against the Chinese source that the surrounding translation itself is accurate (docs-cn: "尽管名称是可重复读隔离级别，但是 TiDB 中可重复读隔离级别和 ANSI 可重复隔离级别是不同的") — only the EN grammar needed fixing, not the meaning. --- transaction-isolation-levels.md | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/transaction-isolation-levels.md b/transaction-isolation-levels.md index a6b52467a8191..3d4acf0600d16 100644 --- a/transaction-isolation-levels.md +++ b/transaction-isolation-levels.md @@ -55,7 +55,7 @@ commit; | ### Difference between TiDB and ANSI Repeatable Read -The Repeatable Read isolation level in TiDB differs from ANSI Repeatable Read isolation level, though they sharing the same name. According to the standard described in the [A Critique of ANSI SQL Isolation Levels](https://www.microsoft.com/en-us/research/wp-content/uploads/2016/02/tr-95-51.pdf) paper, TiDB implements the Snapshot Isolation level. This isolation level does not allow strict phantoms (A3) but allows broad phantoms (P3) and write skews. In contrast, the ANSI Repeatable Read isolation level allows phantom reads but does not allow write skews. +The Repeatable Read isolation level in TiDB differs from the ANSI Repeatable Read isolation level, though they share the same name. According to the standard described in the [A Critique of ANSI SQL Isolation Levels](https://www.microsoft.com/en-us/research/wp-content/uploads/2016/02/tr-95-51.pdf) paper, TiDB implements the Snapshot Isolation level. This isolation level does not allow strict phantoms (A3) but allows broad phantoms (P3) and write skews. In contrast, the ANSI Repeatable Read isolation level allows phantom reads but does not allow write skews. ### Difference between TiDB and MySQL Repeatable Read