Update the default value of tidb_stmt_summary_max_stmt_count (#6021) (#…

…6022)
pingcap · Jul 30, 2021 · 2c75adc · 2c75adc
1 parent 01e9b66
commit 2c75adc
Show file tree

Hide file tree

Showing 3 changed files with 3 additions and 3 deletions.
diff --git a/sql-statements/sql-statement-show-variables.md b/sql-statements/sql-statement-show-variables.md
@@ -129,7 +129,7 @@ mysql> SHOW GLOBAL VARIABLES LIKE 'tidb%';
 | tidb_stmt_summary_history_size      | 24                  |
 | tidb_stmt_summary_internal_query    | 0                   |
 | tidb_stmt_summary_max_sql_length    | 4096                |
-| tidb_stmt_summary_max_stmt_count    | 200                 |
+| tidb_stmt_summary_max_stmt_count    | 3000                |
 | tidb_stmt_summary_refresh_interval  | 1800                |
 | tidb_store_limit                    | 0                   |
 | tidb_txn_mode                       |                     |

diff --git a/statement-summary-tables.md b/statement-summary-tables.md
@@ -101,7 +101,7 @@ The following system variables are used to control the statement summary:
 - `tidb_enable_stmt_summary`: Determines whether to enable the statement summary feature. `1` represents `enable`, and `0` means `disable`. The feature is enabled by default. The statistics in the system table are cleared if this feature is disabled. The statistics are re-calculated next time this feature is enabled. Tests have shown that enabling this feature has little impact on performance.
 - `tidb_stmt_summary_refresh_interval`: The interval at which the `statements_summary` table is refreshed. The time unit is second (s). The default value is `1800`.
 - `tidb_stmt_summary_history_size`: The size of each SQL statement category stored in the `statements_summary_history` table. The default value is `24`.
-- `tidb_stmt_summary_max_stmt_count`: Limits the number of SQL statements that can be stored in statement summary tables. The default value is `200`. If the limit is exceeded, those SQL statements that recently remain unused are cleared.
+- `tidb_stmt_summary_max_stmt_count`: Limits the number of SQL statements that can be stored in statement summary tables. Before v5.1.1, the default value is `200`. Since v5.1.1, the default value is `3000`. If the limit is exceeded, those SQL statements that recently remain unused are cleared.
 - `tidb_stmt_summary_max_sql_length`: Specifies the longest display length of `DIGEST_TEXT` and `QUERY_SAMPLE_TEXT`. The default value is `4096`.
 - `tidb_stmt_summary_internal_query`: Determines whether to count the TiDB SQL statements. `1` means to count, and `0` means not to count. The default value is `0`.
 

diff --git a/system-variables.md b/system-variables.md
@@ -1268,7 +1268,7 @@ SET tidb_slow_log_threshold = 200;
 ### tidb_stmt_summary_max_stmt_count <span class="version-mark">New in v4.0</span>
 
 - Scope: SESSION | GLOBAL
-- Default value: `200`
+- Default value: Before v5.1.1, the default value is `200`. Since v5.1.1, the default value is `3000`.
 - Range: `[1, 32767]`
 - This variable is used to set the maximum number of statements that the statement summary stores in memory.