From b7dd7d978d99d042dbbfcfb890010735ad3e3e3f Mon Sep 17 00:00:00 2001 From: Frank945946 <108602632+Frank945946@users.noreply.github.com> Date: Mon, 9 Mar 2026 15:34:00 +0800 Subject: [PATCH 1/3] Update system-variables.md --- system-variables.md | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/system-variables.md b/system-variables.md index 79af0db79a694..e9b5002f3c595 100644 --- a/system-variables.md +++ b/system-variables.md @@ -5758,7 +5758,7 @@ SHOW WARNINGS; - Applies to hint [SET_VAR](/optimizer-hints.md#set_varvar_namevar_value): No - Type: String - Default value: "" -- Optional value: a string with a length of up to 64 characters. Valid characters include digits `0-9`, letters `a-zA-Z`, underscores `_`, and hyphens `-`. +- Optional value: a string with a length of up to 64 characters. Valid characters include digits `0-9`, letters `a-zA-Z`, underscores `_`, and hyphens `-`. Sinc v8.5.6, the value of this variable is case-insensitive. The system converts the input value to lowercase for storage and comparison. - This variable is an instance-level system variable. You can use it to control the service scope of each TiDB node under the [TiDB Distributed eXecution Framework (DXF)](/tidb-distributed-execution-framework.md). The DXF determines which TiDB nodes can be scheduled to execute distributed tasks based on the value of this variable. For specific rules, see [Task scheduling](/tidb-distributed-execution-framework.md#task-scheduling). ### tidb_session_alias New in v7.4.0 From e34f94a3a2aae96d2d8d14083d36e33c0b471699 Mon Sep 17 00:00:00 2001 From: xixirangrang Date: Mon, 16 Mar 2026 16:31:16 +0800 Subject: [PATCH 2/3] Update system-variables.md Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com> --- system-variables.md | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/system-variables.md b/system-variables.md index e9b5002f3c595..a3c7ebafacbd7 100644 --- a/system-variables.md +++ b/system-variables.md @@ -5758,7 +5758,7 @@ SHOW WARNINGS; - Applies to hint [SET_VAR](/optimizer-hints.md#set_varvar_namevar_value): No - Type: String - Default value: "" -- Optional value: a string with a length of up to 64 characters. Valid characters include digits `0-9`, letters `a-zA-Z`, underscores `_`, and hyphens `-`. Sinc v8.5.6, the value of this variable is case-insensitive. The system converts the input value to lowercase for storage and comparison. +- Optional value: a string with a length of up to 64 characters. Valid characters include digits `0-9`, letters `a-zA-Z`, underscores `_`, and hyphens `-`. Starting from v8.5.6 and v9.0.0, the value of this variable is case-insensitive. TiDB converts the input value to lowercase for storage and comparison. - This variable is an instance-level system variable. You can use it to control the service scope of each TiDB node under the [TiDB Distributed eXecution Framework (DXF)](/tidb-distributed-execution-framework.md). The DXF determines which TiDB nodes can be scheduled to execute distributed tasks based on the value of this variable. For specific rules, see [Task scheduling](/tidb-distributed-execution-framework.md#task-scheduling). ### tidb_session_alias New in v7.4.0 From 3d7f6fddd5d535467d949ba4cd958fefeecf702e Mon Sep 17 00:00:00 2001 From: houfaxin Date: Wed, 1 Apr 2026 17:21:11 +0800 Subject: [PATCH 3/3] Update system-variables.md --- system-variables.md | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/system-variables.md b/system-variables.md index a3c7ebafacbd7..cbc690779e41b 100644 --- a/system-variables.md +++ b/system-variables.md @@ -5868,7 +5868,7 @@ Query OK, 0 rows affected, 1 warning (0.00 sec) > > If the character check is skipped, TiDB might fail to detect invalid UTF-8 characters written by the application, cause decoding errors when `ANALYZE` is executed, and introduce other unknown encoding issues. If your application cannot guarantee the validity of the written string, it is not recommended to skip the character check. -### tidb_slow_log_max_per_sec New in v9.0.0 +### tidb_slow_log_max_per_sec New in v8.5.6 and v9.0.0 - Scope: GLOBAL - Persists to cluster: Yes @@ -5879,9 +5879,9 @@ Query OK, 0 rows affected, 1 warning (0.00 sec) - This variable controls the maximum number of slow query log entries that can be written per TiDB node per second. - A value of `0` means there is no limit on the number of slow query log entries written per second. - A value greater than `0` means TiDB writes at most the specified number of slow query log entries per second. Any excess log entries are discarded and not written to the slow query log file. -- This variable is often used with [`tidb_slow_log_rules`](#tidb_slow_log_rules-new-in-v900) to prevent excessive slow query logs from being generated under high-workload conditions. +- This variable is often used with [`tidb_slow_log_rules`](#tidb_slow_log_rules-new-in-v856-and-v900) to prevent excessive slow query logs from being generated under high-workload conditions. -### tidb_slow_log_rules New in v9.0.0 +### tidb_slow_log_rules New in v8.5.6 and v9.0.0 - Scope: SESSION | GLOBAL - Persists to cluster: Yes @@ -5892,7 +5892,7 @@ Query OK, 0 rows affected, 1 warning (0.00 sec) > **Tip:** > -> After enabling `tidb_slow_log_rules`, it is recommended to also configure [`tidb_slow_log_max_per_sec`](#tidb_slow_log_max_per_sec-new-in-v900) to limit the slow query log output rate and prevent rule-based slow query logging from being triggered too frequently. +> After enabling `tidb_slow_log_rules`, it is recommended to also configure [`tidb_slow_log_max_per_sec`](#tidb_slow_log_max_per_sec-new-in-v856-and-v900) to limit the slow query log output rate and prevent rule-based slow query logging from being triggered too frequently. ### tidb_slow_log_threshold