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sql-statement-drop-stats.md

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DROP STATS
An overview of the usage of DROP STATS for the TiDB database.

DROP STATS

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

Synopsis

DropStatsStmt ::=
    'DROP' 'STATS' TableName  ("PARTITION" partition | "GLOBAL")? ( ',' TableName )*

TableName ::=
    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.

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

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

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

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

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

Examples

CREATE TABLE t(a INT);
Query OK, 0 rows affected (0.01 sec)

SHOW STATS_META WHERE db_name='test' and table_name='t';
+---------+------------+----------------+---------------------+--------------+-----------+
| Db_name | Table_name | Partition_name | Update_time         | Modify_count | Row_count |
+---------+------------+----------------+---------------------+--------------+-----------+
| test    | t          |                | 2020-05-25 20:34:33 |            0 |         0 |
+---------+------------+----------------+---------------------+--------------+-----------+
1 row in set (0.00 sec)

DROP STATS t;
Query OK, 0 rows affected (0.00 sec)

SHOW STATS_META WHERE db_name='test' and table_name='t';
Empty set (0.00 sec)

MySQL compatibility

This statement is a TiDB extension to MySQL syntax.

See also