SHOW STATS_BUCKETS
The SHOW STATS_BUCKETS statement shows the bucket information in statistics.
Currently, the SHOW STATS_BUCKETS statement returns the following columns:
| Column name | Description |
|---|---|
Db_name | The database name |
Table_name | The table name |
Partition_name | The partition name |
Column_name | The column name (when is_index is 0) or the index name (when is_index is 1) |
Is_index | Whether it is an index column or not |
Bucket_id | The ID of a bucket |
Count | The number of all the values that falls on the bucket and the previous buckets |
Repeats | The occurrence number of the maximum value |
Lower_bound | The minimum value |
Upper_bound | The maximum value |
Ndv | The number of different values in the bucket. When tidb_analyze_version = 1, Ndv is always 0, which has no actual meaning. |
Synopsis
- ShowStatsBucketsStmt
- ShowLikeOrWhere
ShowStatsBucketsStmt ::=
"SHOW" "STATS_BUCKETS" ShowLikeOrWhere?
ShowLikeOrWhere ::=
"LIKE" SimpleExpr
| "WHERE" Expression
Examples
SHOW STATS_BUCKETS WHERE Table_name='t';
+---------+------------+----------------+-------------+----------+-----------+-------+---------+--------------------------+--------------------------+------+
| Db_name | Table_name | Partition_name | Column_name | Is_index | Bucket_id | Count | Repeats | Lower_Bound | Upper_Bound | Ndv |
+---------+------------+----------------+-------------+----------+-----------+-------+---------+--------------------------+--------------------------+------+
| test | t | | a | 0 | 0 | 1 | 1 | 2023-12-27 00:00:00 | 2023-12-27 00:00:00 | 0 |
| test | t | | a | 0 | 1 | 2 | 1 | 2023-12-28 00:00:00 | 2023-12-28 00:00:00 | 0 |
| test | t | | ia | 1 | 0 | 1 | 1 | (NULL, 2) | (NULL, 2) | 0 |
| test | t | | ia | 1 | 1 | 2 | 1 | (NULL, 4) | (NULL, 4) | 0 |
| test | t | | ia | 1 | 2 | 3 | 1 | (2023-12-27 00:00:00, 1) | (2023-12-27 00:00:00, 1) | 0 |
| test | t | | ia | 1 | 3 | 4 | 1 | (2023-12-28 00:00:00, 3) | (2023-12-28 00:00:00, 3) | 0 |
+---------+------------+----------------+-------------+----------+-----------+-------+---------+--------------------------+--------------------------+------+
6 rows in set (0.00 sec)
MySQL compatibility
This statement is a TiDB extension to MySQL syntax.