UNLOCK STATS

UNLOCK STATS is used to unlock the statistics of a table or tables.

Synopsis

UnlockStatsStmt
UNLOCKSTATSTableNameListTableNamePARTITIONPartitionNameList
TableNameList
TableName,
TableName
Identifier.Identifier
PartitionNameList
Identifier,

Examples

Refer to the examples in LOCK STATS and create a table t and lock its statistics.

Unlock the statistics of table t, and ANALYZE can be successfully executed.

mysql> UNLOCK STATS t; Query OK, 0 rows affected (0.01 sec) mysql> ANALYZE TABLE t; Query OK, 0 rows affected, 1 warning (0.03 sec) mysql> SHOW WARNINGS; +-------+------+-----------------------------------------------------------------------------------------------------------------------------------------+ | Level | Code | Message | +-------+------+-----------------------------------------------------------------------------------------------------------------------------------------+ | Note | 1105 | Analyze use auto adjusted sample rate 1.000000 for table test.t, reason to use this rate is "use min(1, 110000/8) as the sample-rate=1" | +-------+------+-----------------------------------------------------------------------------------------------------------------------------------------+ 1 row in set (0.00 sec)

Refer to examples in LOCK STATS and create a table t and lock the statistics of its partition p1.

Unlock the statistics of partition p1, and ANALYZE can be successfully executed.

mysql> UNLOCK STATS t PARTITION p1; Query OK, 0 rows affected (0.00 sec) mysql> ANALYZE TABLE t PARTITION p1; Query OK, 0 rows affected, 1 warning (0.01 sec) mysql> SHOW WARNINGS; +-------+------+----------------------------------------------------------------------------------------------------------------------------------------------------------------------+ | Level | Code | Message | +-------+------+----------------------------------------------------------------------------------------------------------------------------------------------------------------------+ | Note | 1105 | Analyze use auto adjusted sample rate 1.000000 for table test.t's partition p1, reason to use this rate is "TiDB assumes that the table is empty, use sample-rate=1" | +-------+------+----------------------------------------------------------------------------------------------------------------------------------------------------------------------+ 1 row in set (0.00 sec)

MySQL compatibility

This statement is a TiDB extension to MySQL syntax.

See also