SHOW COLUMN_STATS_USAGE
The SHOW COLUMN_STATS_USAGE statement shows the last usage time and collection time of column statistics. You can also use it to locate PREDICATE COLUMNS and columns on which statistics have been collected.
Currently, the SHOW COLUMN_STATS_USAGE 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 |
Last_used_at | The last time when the column statistics were used in the query optimization |
Last_analyzed_at | The last time when the column statistics were collected |
Synopsis
- ShowColumnStatsUsageStmt
- ShowLikeOrWhere
ShowColumnStatsUsageStmt ::=
"SHOW" "COLUMN_STATS_USAGE" ShowLikeOrWhere?
ShowLikeOrWhere ::=
"LIKE" SimpleExpr
| "WHERE" Expression
Examples
SHOW COLUMN_STATS_USAGE;
+---------+------------+----------------+-------------+--------------+---------------------+
| Db_name | Table_name | Partition_name | Column_name | Last_used_at | Last_analyzed_at |
+---------+------------+----------------+-------------+--------------+---------------------+
| test | t1 | | id | NULL | 2024-05-10 11:04:23 |
| test | t1 | | b | NULL | 2024-05-10 11:04:23 |
| test | t1 | | pad | NULL | 2024-05-10 11:04:23 |
| test | t | | a | NULL | 2024-05-10 11:37:06 |
| test | t | | b | NULL | 2024-05-10 11:37:06 |
+---------+------------+----------------+-------------+--------------+---------------------+
5 rows in set (0.00 sec)
MySQL compatibility
This statement is a TiDB extension to MySQL syntax.