SHOW STATS_LOCKED

SHOW STATS_LOCKED shows the tables whose statistics are locked.

Currently, the SHOW STATS_LOCKED statement returns the following columns:

Column nameDescription
Db_nameThe database name
Table_nameThe table name
Partition_nameThe partition name
StatusThe statistics status, such as locked

Synopsis

ShowStatsLockedStmt
SHOWSTATS_LOCKEDShowLikeOrWhereOpt
ShowLikeOrWhereOpt
LIKESimpleExprWHEREExpression

Examples

Create table t, and insert data into it. When the statistics of table t are not locked, the ANALYZE statement can be successfully executed.

mysql> CREATE TABLE t(a INT, b INT); Query OK, 0 rows affected (0.03 sec) mysql> INSERT INTO t VALUES (1,2), (3,4), (5,6), (7,8); Query OK, 4 rows affected (0.00 sec) Records: 4 Duplicates: 0 Warnings: 0 mysql> ANALYZE TABLE t; Query OK, 0 rows affected, 1 warning (0.02 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 "Row count in stats_meta is much smaller compared with the row count got by PD, use min(1, 15000/4) as the sample-rate=1" | +-------+------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+ 1 row in set (0.00 sec)

Lock the statistics of table t and execute SHOW STATS_LOCKED. The output shows that the statistics of table t have been locked.

mysql> LOCK STATS t; Query OK, 0 rows affected (0.00 sec) mysql> SHOW STATS_LOCKED; +---------+------------+----------------+--------+ | Db_name | Table_name | Partition_name | Status | +---------+------------+----------------+--------+ | test | t | | locked | +---------+------------+----------------+--------+ 1 row in set (0.01 sec)

MySQL compatibility

This statement is a TiDB extension to MySQL syntax.

See also

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