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 nameDescription
Db_nameThe database name
Table_nameThe table name
Partition_nameThe partition name
Column_nameThe column name (when is_index is 0) or the index name (when is_index is 1)
Is_indexWhether it is an index column or not
Bucket_idThe ID of a bucket
CountThe number of all the values that falls on the bucket and the previous buckets
RepeatsThe occurrence number of the maximum value
Lower_boundThe minimum value
Upper_boundThe maximum value
NdvThe number of different values in the bucket. When tidb_analyze_version = 1, Ndv is always 0, which has no actual meaning.

Synopsis

ShowStatsBucketsStmt

SHOW STATS_BUCKETS - 图1

ShowLikeOrWhere

SHOW STATS_BUCKETS - 图2

  1. ShowStatsBucketsStmt ::=
  2.     "SHOW" "STATS_BUCKETS" ShowLikeOrWhere?
  4. ShowLikeOrWhere ::=
  5.     "LIKE" SimpleExpr
  6. |   "WHERE" Expression

Examples

  1. SHOW STATS_BUCKETS WHERE Table_name='t';
  1. +---------+------------+----------------+-------------+----------+-----------+-------+---------+--------------------------+--------------------------+------+
  2. | Db_name | Table_name | Partition_name | Column_name | Is_index | Bucket_id | Count | Repeats | Lower_Bound              | Upper_Bound              | Ndv  |
  3. +---------+------------+----------------+-------------+----------+-----------+-------+---------+--------------------------+--------------------------+------+
  4. | test    | t          |                | a           |        0 |         0 |     1 |       1 | 2023-12-27 00:00:00      | 2023-12-27 00:00:00      |    0 |
  5. | test    | t          |                | a           |        0 |         1 |     2 |       1 | 2023-12-28 00:00:00      | 2023-12-28 00:00:00      |    0 |
  6. | test    | t          |                | ia          |        1 |         0 |     1 |       1 | (NULL, 2)                | (NULL, 2)                |    0 |
  7. | test    | t          |                | ia          |        1 |         1 |     2 |       1 | (NULL, 4)                | (NULL, 4)                |    0 |
  8. | test    | t          |                | ia          |        1 |         2 |     3 |       1 | (2023-12-27 00:00:00, 1) | (2023-12-27 00:00:00, 1) |    0 |
  9. | test    | t          |                | ia          |        1 |         3 |     4 |       1 | (2023-12-28 00:00:00, 3) | (2023-12-28 00:00:00, 3) |    0 |
  10. +---------+------------+----------------+-------------+----------+-----------+-------+---------+--------------------------+--------------------------+------+
  11. 6 rows in set (0.00 sec)

MySQL compatibility

This statement is a TiDB extension to MySQL syntax.

See also