From c2af846cb367c509ad6ae9f9a3f347c21a29a0eb Mon Sep 17 00:00:00 2001 From: Lilian Lee Date: Thu, 29 Aug 2024 16:43:36 +0800 Subject: [PATCH] releases: add the change of "max_execution_time" (#18695) --- releases/release-6.4.0.md | 1 + system-variables.md | 2 +- 2 files changed, 2 insertions(+), 1 deletion(-) diff --git a/releases/release-6.4.0.md b/releases/release-6.4.0.md index 08fce00ba076f..1984ea9e849f0 100644 --- a/releases/release-6.4.0.md +++ b/releases/release-6.4.0.md @@ -278,6 +278,7 @@ In v6.4.0-DMR, the key new features and improvements are as follows: | Variable name | Change type | Description | |--------|------------------------------|------| +| [`max_execution_time`](/system-variables.md#max_execution_time) | Modified | Before v6.4.0, this variable takes effect on all types of statements. Starting from v6.4.0, this variable only controls the maximum execution time of read-only statements. | | [`tidb_constraint_check_in_place_pessimistic`](/system-variables.md#tidb_constraint_check_in_place_pessimistic-new-in-v630) | Modified | Removes the GLOBAL scope and allows you to modify the default value using the [`pessimistic-txn.constraint-check-in-place-pessimistic`](/tidb-configuration-file.md#constraint-check-in-place-pessimistic-new-in-v640) configuration item. This variable controls when TiDB checks the unique constraints in pessimistic transactions. | | [`tidb_ddl_flashback_concurrency`](/system-variables.md#tidb_ddl_flashback_concurrency-new-in-v630) | Modified | Takes effect starting from v6.4.0 and controls the concurrency of [`FLASHBACK CLUSTER TO TIMESTAMP`](/sql-statements/sql-statement-flashback-cluster.md). The default value is `64`. | | [`tidb_enable_clustered_index`](/system-variables.md#tidb_enable_clustered_index-new-in-v50) | Modified | Changes the default value from `INT_ONLY` to `ON`, meaning that primary keys are created as clustered indexes by default.| diff --git a/system-variables.md b/system-variables.md index fd724b9841b45..0eccde072d4f6 100644 --- a/system-variables.md +++ b/system-variables.md @@ -737,7 +737,7 @@ This variable is an alias for [`last_insert_id`](#last_insert_id). > **Note:** > -> The `max_execution_time` system variable currently only controls the maximum execution time for read-only SQL statements. The precision of the timeout value is roughly 100ms. This means the statement might not be terminated in accurate milliseconds as you specify. +> Before v6.4.0, the `max_execution_time` system variable takes effect on all types of statements. Starting from v6.4.0, this variable only controls the maximum execution time of read-only statements. The precision of the timeout value is roughly 100ms. This means the statement might not be terminated in exact milliseconds as you specify.