DROP STATS

The DROP STATS statement is used to delete the statistics of the selected table from the selected database.

Synopsis

DropStatsStmt

DROP STATS - 图1

TableName

DROP STATS - 图2

  1. DropStatsStmt ::=
  2.     'DROP' 'STATS' TableName  ("PARTITION" partition | "GLOBAL")? ( ',' TableName )*
  4. TableName ::=
  5.     Identifier ('.' Identifier)?

Usage

The following statement deletes all statistics of TableName. If a partitioned table is specified, this statement deletes statistics of all partitions in this table as well as GlobalStats generated in dynamic pruning mode.

  1. DROP STATS TableName
  1. Query OK, 0 rows affected (0.00 sec)

The following statement only deletes statistics of the specified partitions in PartitionNameList.

  1. DROP STATS TableName PARTITION PartitionNameList;
  1. Query OK, 0 rows affected (0.00 sec)

The following statement only deletes GlobalStats generated in dynamic pruning mode of the specified table.

  1. DROP STATS TableName GLOBAL;
  1. Query OK, 0 rows affected (0.00 sec)

Examples

  1. CREATE TABLE t(a INT);
  1. Query OK, 0 rows affected (0.01 sec)
  1. SHOW STATS_META WHERE db_name='test' and table_name='t';
  1. +---------+------------+----------------+---------------------+--------------+-----------+
  2. | Db_name | Table_name | Partition_name | Update_time         | Modify_count | Row_count |
  3. +---------+------------+----------------+---------------------+--------------+-----------+
  4. | test    | t          |                | 2020-05-25 20:34:33 |            0 |         0 |
  5. +---------+------------+----------------+---------------------+--------------+-----------+
  6. 1 row in set (0.00 sec)
  1. DROP STATS t;
  1. Query OK, 0 rows affected (0.00 sec)
  1. SHOW STATS_META WHERE db_name='test' and table_name='t';
  1. Empty set (0.00 sec)

MySQL compatibility

This statement is a TiDB extension to MySQL syntax.

See also