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statistics: add tidb_enable_stats_owner #19460

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Jan 16, 2025
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statistics: add tidb_enable_stats_owner #19460

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statistics: add tidb_enable_stats_owner
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7 changes: 4 additions & 3 deletions statistics.md
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Expand Up @@ -28,16 +28,17 @@ TiDB persists the update information every 60 seconds.

</CustomContent>

Based upon the number of changes to a table, TiDB will automatically schedule [`ANALYZE`](/sql-statements/sql-statement-analyze-table.md) to collect statistics on those tables. This is controlled by the [`tidb_enable_auto_analyze`](/system-variables.md#tidb_enable_auto_analyze-new-in-v610) system variable and the following `tidb_auto_analyze%` variables.
Based upon the number of changes to a table, TiDB will automatically schedule [`ANALYZE`](/sql-statements/sql-statement-analyze-table.md) to collect statistics on those tables. This is controlled by the following system variables.

| System Variable | Default Value | Description |
|---|---|---|
| [`tidb_enable_auto_analyze`](/system-variables.md#tidb_enable_auto_analyze-new-in-v610) | `ON` | Controls whether TiDB automatically executes `ANALYZE`. |
| [`tidb_auto_analyze_end_time`](/system-variables.md#tidb_auto_analyze_end_time) | `23:59 +0000` | The end time in a day when TiDB can perform automatic updates. |
| [`tidb_auto_analyze_ratio`](/system-variables.md#tidb_auto_analyze_ratio) | `0.5` | The threshold value of automatic update. |
| [`tidb_auto_analyze_start_time`](/system-variables.md#tidb_auto_analyze_start_time) | `00:00 +0000` | The start time in a day when TiDB can perform automatic update. |
| [`tidb_auto_analyze_end_time`](/system-variables.md#tidb_auto_analyze_end_time) | `23:59 +0000` | The end time in a day when TiDB can perform automatic update. |
| [`tidb_auto_analyze_partition_batch_size`](/system-variables.md#tidb_auto_analyze_partition_batch_size-new-in-v640) | `128` | The number of partitions that TiDB automatically analyzes when analyzing a partitioned table (that is, when automatically updating statistics on a partitioned table). |
| [`tidb_enable_auto_analyze`](/system-variables.md#tidb_enable_auto_analyze-new-in-v610) | `ON` | Controls whether TiDB automatically executes `ANALYZE`. |
| [`tidb_enable_auto_analyze_priority_queue`](/system-variables.md#tidb_enable_auto_analyze_priority_queue-new-in-v800) | `ON` | Controls whether to enable the priority queue to schedule the tasks of automatically collecting statistics. When this variable is enabled, TiDB prioritizes collecting statistics for tables that are more valuable to collect, such as newly created indexes and partitioned tables with partition changes. Additionally, TiDB prioritizes tables with lower health scores, placing them at the front of the queue. |
| [`tidb_enable_stats_owner`](/system-variables.md#tidb_enable_stats_owner-new-in-v840) | `ON` | Controls whether the corresponding TiDB instance can run [automatic statistics update](/statistics.md#automatic-update) tasks. |
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When the ratio of the number of modified rows to the total number of rows of `tbl` in a table is greater than `tidb_auto_analyze_ratio`, and the current time is between `tidb_auto_analyze_start_time` and `tidb_auto_analyze_end_time`, TiDB executes the `ANALYZE TABLE tbl` statement in the background to automatically update the statistics on this table.

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