diff --git a/privilege-management.md b/privilege-management.md index 4c753ccb29ae..64aadb49ea53 100644 --- a/privilege-management.md +++ b/privilege-management.md @@ -398,6 +398,14 @@ SELECT * FROM INFORMATION_SCHEMA.USER_PRIVILEGES WHERE grantee = "'root'@'%'"; 需要对所操作的表拥有 `INSERT` 和 `SELECT` 权限。 +### LOCK STATS + +需要对所操作的表拥有 `INSERT` 和 `SELECT` 权限。 + +### UNLOCK STATS + +需要对所操作的表拥有 `INSERT` 和 `SELECT` 权限。 + ### SHOW `SHOW CREATE TABLE` 需要任意一种权限。 @@ -410,6 +418,8 @@ SELECT * FROM INFORMATION_SCHEMA.USER_PRIVILEGES WHERE grantee = "'root'@'%'"; `SHOW IMPORT JOB` 需要 `SUPER` 权限来显示属于其他用户的任务，否则只能看到当前用户创建的任务。 +`SHOW STATS_LOCKED` 需要拥有 `mysql.stats_table_locked` 表的 `SELECT` 权限。 + ### CREATE ROLE/USER `CREATE ROLE` 需要 `CREATE ROLE` 权限。 diff --git a/sql-statements/sql-statement-lock-stats.md b/sql-statements/sql-statement-lock-stats.md index 6ab97d7c236f..821c1aa15021 100644 --- a/sql-statements/sql-statement-lock-stats.md +++ b/sql-statements/sql-statement-lock-stats.md @@ -5,23 +5,22 @@ summary: TiDB 数据库中 LOCK STATS 的使用概况。 # LOCK STATS -`LOCK STATS` 语句用于锁定统计信息。 - -> **警告：** -> -> 锁定统计信息目前为实验特性，不建议在生产环境中使用。 +`LOCK STATS` 语句用于锁定表或分区的统计信息，使得在锁定期间，TiDB 不会自动更新统计信息。具体行为请参见[锁定统计信息的行为说明](/statistics.md#锁定统计信息的行为说明) ## 语法图 ```ebnf+diagram LockStatsStmt ::= - 'LOCK' 'STATS' TableNameList + 'LOCK' 'STATS' (TableNameList) | (TableName 'PARTITION' PartitionNameList) TableNameList ::= TableName (',' TableName)* TableName ::= Identifier ( '.' Identifier )? + +PartitionNameList ::= + Identifier ( ',' Identifier )* ``` ## 示例 @@ -29,32 +28,32 @@ TableName ::= 创建表 `t`，插入一些数据，在未锁定表 `t` 的统计信息的情况下成功执行 `ANALYZE` 语句。 ```sql -mysql> create table t(a int, b int); +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); +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; +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 | -+-------+------+-----------------------------------------------------------------+ +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) ``` 锁定表 `t` 的统计信息，执行 `ANALYZE` 语句，warning 提示跳过对表 `t` 的 `ANALYZE`。 ```sql -mysql> lock stats t; +mysql> LOCK STATS t; Query OK, 0 rows affected (0.00 sec) -mysql> show stats_locked; +mysql> SHOW STATS_LOCKED; +---------+------------+----------------+--------+ | Db_name | Table_name | Partition_name | Status | +---------+------------+----------------+--------+ @@ -62,37 +61,77 @@ mysql> show stats_locked; +---------+------------+----------------+--------+ 1 row in set (0.01 sec) -mysql> analyze table t; +mysql> ANALYZE TABLE t; Query OK, 0 rows affected, 2 warnings (0.00 sec) -mysql> show warnings; -+---------+------+-----------------------------------------------------------------+ -| Level | Code | Message | -+---------+------+-----------------------------------------------------------------+ -| Note | 1105 | Analyze use auto adjusted sample rate 1.000000 for table test.t | -| Warning | 1105 | skip analyze locked table: t | -+---------+------+-----------------------------------------------------------------+ +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" | +| Warning | 1105 | skip analyze locked table: test.t | ++---------+------+-----------------------------------------------------------------------------------------------------------------------------------------+ 2 rows in set (0.00 sec) ``` -解锁表 `t` 的统计信息，成功执行 `ANALYZE` 语句。 +另外，你也可以通过 `LOCK STATS` 语句锁定分区的统计信息。用例如下： + +创建分区表 `t`，插入一些数据，在未锁定分区 `p1` 的统计信息的情况下成功执行 `ANALYZE` 语句。 + +```sql +mysql> CREATE TABLE t(a INT, b INT) PARTITION BY RANGE (a) (PARTITION p0 VALUES LESS THAN (10), PARTITION p1 VALUES LESS THAN (20), PARTITION p2 VALUES LESS THAN (30)); +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, 6 warning (0.02 sec) + +mysql> SHOW WARNINGS; ++---------+------+--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+ +| Level | Code | Message | ++---------+------+--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+ +| Warning | 1105 | disable dynamic pruning due to t has no global stats | +| Note | 1105 | Analyze use auto adjusted sample rate 1.000000 for table test.t's partition p0, 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" | +| Warning | 1105 | disable dynamic pruning due to t has no global stats | +| 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" | +| Warning | 1105 | disable dynamic pruning due to t has no global stats | +| Note | 1105 | Analyze use auto adjusted sample rate 1.000000 for table test.t's partition p2, reason to use this rate is "TiDB assumes that the table is empty, use sample-rate=1" | ++---------+------+--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+ +6 rows in set (0.01 sec) +``` + +锁定分区 `p1` 的统计信息，执行 `ANALYZE` 语句，warning 提示跳过对分区 `p1` 的 `ANALYZE`。 ```sql -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 | -+-------+------+-----------------------------------------------------------------+ +mysql> LOCK STATS t PARTITION p1; +Query OK, 0 rows affected (0.00 sec) + +mysql> SHOW STATS_LOCKED; ++---------+------------+----------------+--------+ +| Db_name | Table_name | Partition_name | Status | ++---------+------------+----------------+--------+ +| test | t | p1 | locked | ++---------+------------+----------------+--------+ 1 row in set (0.00 sec) + +mysql> ANALYZE TABLE t PARTITION p1; +Query OK, 0 rows affected, 2 warnings (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" | +| Warning | 1105 | skip analyze locked table: test.t partition (p1) | ++---------+------+----------------------------------------------------------------------------------------------------------------------------------------------------------------------+ +2 rows in set (0.00 sec) ``` +解锁统计信息请参考 [UNLOCK STATS](/sql-statements/sql-statement-unlock-stats.md)。 + ## MySQL 兼容性 该语句是 TiDB 对 MySQL 语法的扩展。 diff --git a/sql-statements/sql-statement-show-stats-locked.md b/sql-statements/sql-statement-show-stats-locked.md index f607c196b272..20378f8d6084 100644 --- a/sql-statements/sql-statement-show-stats-locked.md +++ b/sql-statements/sql-statement-show-stats-locked.md @@ -7,10 +7,6 @@ summary: TiDB 数据库中 SHOW STATS_LOCKED 的使用概况。 `SHOW STATS_LOCKED` 语句显示统计信息被锁定的表。 -> **警告：** -> -> 锁定统计信息目前为实验特性，不建议在生产环境中使用。 - ## 语法图 ```ebnf+diagram @@ -24,68 +20,38 @@ ShowLikeOrWhereOpt ::= 'LIKE' SimpleExpr | 'WHERE' Expression 创建表 `t`，插入一些数据，在未锁定表 `t` 的统计信息的情况下成功执行 `ANALYZE` 语句。 ```sql -mysql> create table t(a int, b int); +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); +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; +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 | -+-------+------+-----------------------------------------------------------------+ +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) ``` -锁定表 `t` 的统计信息，执行 `ANALYZE` 语句，使用 `SHOW STATS_LOCKED` 可查看表 `t` 的统计信息已被锁定。warning 提示跳过对表 `t` 的 `ANALYZE`。 +锁定表 `t` 的统计信息，执行 `SHOW STATS_LOCKED` 语句，显示表 `t` 的统计信息被锁定。 ```sql -mysql> lock stats t; +mysql> LOCK STATS t; Query OK, 0 rows affected (0.00 sec) -mysql> show stats_locked; +mysql> SHOW STATS_LOCKED; +---------+------------+----------------+--------+ | Db_name | Table_name | Partition_name | Status | +---------+------------+----------------+--------+ | test | t | | locked | +---------+------------+----------------+--------+ 1 row in set (0.01 sec) - -mysql> analyze table t; -Query OK, 0 rows affected, 2 warnings (0.00 sec) - -mysql> show warnings; -+---------+------+-----------------------------------------------------------------+ -| Level | Code | Message | -+---------+------+-----------------------------------------------------------------+ -| Note | 1105 | Analyze use auto adjusted sample rate 1.000000 for table test.t | -| Warning | 1105 | skip analyze locked table: t | -+---------+------+-----------------------------------------------------------------+ -2 rows in set (0.00 sec) -``` - -解锁表 `t` 的统计信息，成功执行 `ANALYZE` 语句。 - -```sql -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 | -+-------+------+-----------------------------------------------------------------+ -1 row in set (0.00 sec) ``` ## MySQL 兼容性 diff --git a/sql-statements/sql-statement-unlock-stats.md b/sql-statements/sql-statement-unlock-stats.md index debc36bfbcbe..c2d7486a57c5 100644 --- a/sql-statements/sql-statement-unlock-stats.md +++ b/sql-statements/sql-statement-unlock-stats.md @@ -7,89 +7,61 @@ summary: TiDB 数据库中 UNLOCK STATS 的使用概况。 `UNLOCK STATS` 语句用于解锁统计信息被锁定的表。 -> **警告：** -> -> 锁定统计信息目前为实验特性，不建议在生产环境中使用。 - ## 语法图 ```ebnf+diagram UnlockStatsStmt ::= - 'UNLOCK' 'STATS' TableNameList + 'UNLOCK' 'STATS' (TableNameList) | (TableName 'PARTITION' PartitionNameList) TableNameList ::= TableName (',' TableName)* TableName ::= Identifier ( '.' Identifier )? + +PartitionNameList ::= + Identifier ( ',' Identifier )* ``` ## 示例 -创建表 `t`，插入一些数据，在未锁定表 `t` 的统计信息的情况下成功执行 `ANALYZE` 语句。 +参考 [LOCK STATS](/sql-statements/sql-statement-lock-stats.md) 语句的示例来创建表 `t`，并锁定表 `t` 的统计信息。 -```sql -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 | -+-------+------+-----------------------------------------------------------------+ -1 row in set (0.00 sec) -``` - -锁定表 `t` 的统计信息，执行 `ANALYZE` 语句，warning 提示跳过对表 `t` 的 `ANALYZE`。 +解锁表 `t` 的统计信息，成功执行 `ANALYZE` 语句。 ```sql -mysql> lock stats t; -Query OK, 0 rows affected (0.00 sec) +mysql> UNLOCK STATS t; +Query OK, 0 rows affected (0.01 sec) -mysql> show stats_locked; -+---------+------------+----------------+--------+ -| Db_name | Table_name | Partition_name | Status | -+---------+------------+----------------+--------+ -| test | t | | locked | -+---------+------------+----------------+--------+ -1 row in set (0.01 sec) - -mysql> analyze table t; -Query OK, 0 rows affected, 2 warnings (0.00 sec) - -mysql> show warnings; -+---------+------+-----------------------------------------------------------------+ -| Level | Code | Message | -+---------+------+-----------------------------------------------------------------+ -| Note | 1105 | Analyze use auto adjusted sample rate 1.000000 for table test.t | -| Warning | 1105 | skip analyze locked table: t | -+---------+------+-----------------------------------------------------------------+ -2 rows in set (0.00 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) ``` -解锁表 `t` 的统计信息，成功执行 `ANALYZE` 语句。 +参考 [LOCK STATS](/sql-statements/sql-statement-lock-stats.md) 语句的示例来创建表 `t`，并锁定表 `t` 的分区 `p1` 的统计信息。 + +解锁分区 `p1` 的统计信息，成功执行 `ANALYZE` 语句。 ```sql -mysql> unlock stats t; -Query OK, 0 rows affected (0.01 sec) +mysql> UNLOCK STATS t PARTITION p1; +Query OK, 0 rows affected (0.00 sec) -mysql> analyze table t; -Query OK, 0 rows affected, 1 warning (0.03 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 | -+-------+------+-----------------------------------------------------------------+ +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) ``` diff --git a/statistics.md b/statistics.md index fae537c32bd9..c63d7f672562 100644 --- a/statistics.md +++ b/statistics.md @@ -303,7 +303,7 @@ ANALYZE TABLE TableName INDEX [IndexNameList] [WITH NUM BUCKETS|TOPN|CMSKETCH DE > - 若某些列的统计信息合并过程中，缺少某些分区在该列上的统计信息（在不同分区上 analyze 时指定了不同的列），会停止生成 GlobalStats，并通过 warning 信息提示用户缺少列在分区上的统计信息。 > > - 当触发 GlobalStats 更新时，如果 [`tidb_skip_missing_partition_stats`](/system-variables.md#tidb_skip_missing_partition_stats-从-v730-版本开始引入) 开启： -> +> > 如果某些分区缺失全部或者部分列的统计信息，TiDB 生成 GlobalStats 时会跳过缺失的分区统计信息，不影响 GlobalStats 生成。 > > - 在动态裁剪模式开启的情况下，分区和表的 ANALYZE 配置需要保持一致，因此 ANALYZE TABLE TableName PARTITION PartitionNameList 命令后指定的 COLUMNS 配置和 WITH 后指定的 OPTIONS 配置将被忽略，并会通过 warning 信息提示用户。 @@ -373,7 +373,7 @@ ANALYZE INCREMENTAL TABLE TableName PARTITION PartitionNameList INDEX [IndexName - 如果 [`enable-global-kill`](/tidb-configuration-file.md#enable-global-kill-从-v610-版本开始引入) 的值为 `true` (默认为 `true`），你可以直接执行 `KILL TIDB ${id};` 语句。其中，${id} 为上一步中查询得到的后台 `ANALYZE` 任务的 `ID`。 - 如果 `enable-global-kill` 的值为 `false`，你需要先使用客户端连接到执行后台 `ANALYZE` 任务的 TiDB 实例，然后再执行 `KILL TIDB ${id};` 语句。如果使用客户端连接到其他 TiDB 实例，或者客户端和 TiDB 中间有代理，`KILL` 语句不能终止后台的 `ANALYZE` 任务。 - + 关于 `KILL` 语句的更多信息，请参考 [`KILL [TIDB]`](/sql-statements/sql-statement-kill.md)。 ### 控制 ANALYZE 并发度 @@ -497,9 +497,9 @@ SHOW ANALYZE STATUS [ShowLikeOrWhere]; ```sql mysql> SHOW ANALYZE STATUS [ShowLikeOrWhere]; +--------------+------------+----------------+-------------------------------------------------------------------------------------------+----------------+---------------------+---------------------+----------+-------------------------------------------------------------------------------| -| Table_schema | Table_name | Partition_name | Job_info | Processed_rows | Start_time | End_time | State | Fail_reason | +| Table_schema | Table_name | Partition_name | Job_info | Processed_rows | Start_time | End_time | State | Fail_reason | +--------------+------------+----------------+-------------------------------------------------------------------------------------------+----------------+---------------------+---------------------+----------+-------------------------------------------------------------------------------| -| test | sbtest1 | | retry auto analyze table all columns with 100 topn, 0.055 samplerate | 2000000 | 2022-05-07 16:41:09 | 2022-05-07 16:41:20 | finished | NULL | +| test | sbtest1 | | retry auto analyze table all columns with 100 topn, 0.055 samplerate | 2000000 | 2022-05-07 16:41:09 | 2022-05-07 16:41:20 | finished | NULL | | test | sbtest1 | | auto analyze table all columns with 100 topn, 0.5 samplerate | 0 | 2022-05-07 16:40:50 | 2022-05-07 16:41:09 | failed | analyze panic due to memory quota exceeds, please try with smaller samplerate | ``` @@ -756,41 +756,37 @@ LOAD STATS 'file_name'; ## 锁定统计信息 -> **警告：** -> -> 锁定统计信息目前为实验特性，不建议在生产环境中使用。 - -从 v6.5.0 开始，TiDB 引入了锁定统计信息的特性。当一张表的统计信息被锁定以后，该表的统计信息将无法被修改，也无法对该表进行 `ANALYZE` 操作。用例如下： +从 v6.5.0 开始，TiDB 引入了锁定统计信息的特性。当一张表或一个分区的统计信息被锁定以后，该表或分区的统计信息将无法被修改，也无法对该表进行 `ANALYZE` 操作。用例如下： 创建表 `t`，插入一些数据，在未锁定表 `t` 的统计信息的情况下成功执行 `ANALYZE` 语句。 ```sql -mysql> create table t(a int, b int); +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); +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; +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 | -+-------+------+-----------------------------------------------------------------+ +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) ``` 锁定表 `t` 的统计信息，执行 `ANALYZE` 语句，warning 提示跳过对表 `t` 的 `ANALYZE`。 ```sql -mysql> lock stats t; +mysql> LOCK STATS t; Query OK, 0 rows affected (0.00 sec) -mysql> show stats_locked; +mysql> SHOW STATS_LOCKED; +---------+------------+----------------+--------+ | Db_name | Table_name | Partition_name | Status | +---------+------------+----------------+--------+ @@ -798,37 +794,124 @@ mysql> show stats_locked; +---------+------------+----------------+--------+ 1 row in set (0.01 sec) -mysql> analyze table t; +mysql> ANALYZE TABLE t; Query OK, 0 rows affected, 2 warnings (0.00 sec) -mysql> show warnings; -+---------+------+-----------------------------------------------------------------+ -| Level | Code | Message | -+---------+------+-----------------------------------------------------------------+ -| Note | 1105 | Analyze use auto adjusted sample rate 1.000000 for table test.t | -| Warning | 1105 | skip analyze locked table: t | -+---------+------+-----------------------------------------------------------------+ +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" | +| Warning | 1105 | skip analyze locked table: test.t | ++---------+------+-----------------------------------------------------------------------------------------------------------------------------------------+ 2 rows in set (0.00 sec) ``` 解锁表 `t` 的统计信息，成功执行 `ANALYZE` 语句。 ```sql -mysql> unlock stats t; +mysql> UNLOCK STATS t; Query OK, 0 rows affected (0.01 sec) -mysql> analyze table t; +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 | -+-------+------+-----------------------------------------------------------------+ +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) ``` +另外，你也可以通过 `LOCK STATS` 语句锁定分区的统计信息。用例如下： + +创建分区表 `t`，插入一些数据，在未锁定分区 `p1` 的统计信息的情况下成功执行 `ANALYZE` 语句。 + +```sql +mysql> CREATE TABLE t(a INT, b INT) PARTITION BY RANGE (a) (PARTITION p0 VALUES LESS THAN (10), PARTITION p1 VALUES LESS THAN (20), PARTITION p2 VALUES LESS THAN (30)); +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, 6 warning (0.02 sec) + +mysql> SHOW WARNINGS; ++---------+------+--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+ +| Level | Code | Message | ++---------+------+--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+ +| Warning | 1105 | disable dynamic pruning due to t has no global stats | +| Note | 1105 | Analyze use auto adjusted sample rate 1.000000 for table test.t's partition p0, 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" | +| Warning | 1105 | disable dynamic pruning due to t has no global stats | +| 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" | +| Warning | 1105 | disable dynamic pruning due to t has no global stats | +| Note | 1105 | Analyze use auto adjusted sample rate 1.000000 for table test.t's partition p2, reason to use this rate is "TiDB assumes that the table is empty, use sample-rate=1" | ++---------+------+--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+ +6 rows in set (0.01 sec) +``` + +锁定分区 `p1` 的统计信息，执行 `ANALYZE` 语句，warning 提示跳过对分区 `p1` 的 `ANALYZE`。 + +```sql +mysql> LOCK STATS t PARTITION p1; +Query OK, 0 rows affected (0.00 sec) + +mysql> SHOW STATS_LOCKED; ++---------+------------+----------------+--------+ +| Db_name | Table_name | Partition_name | Status | ++---------+------------+----------------+--------+ +| test | t | p1 | locked | ++---------+------------+----------------+--------+ +1 row in set (0.00 sec) + +mysql> ANALYZE TABLE t PARTITION p1; +Query OK, 0 rows affected, 2 warnings (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" | +| Warning | 1105 | skip analyze locked table: test.t partition (p1) | ++---------+------+----------------------------------------------------------------------------------------------------------------------------------------------------------------------+ +2 rows in set (0.00 sec) +``` + +解锁分区 `p1` 的统计信息，成功执行 `ANALYZE` 语句。 + +```sql +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) +``` + +### 锁定统计信息的行为说明 + +* 如果统计信息在分区表上锁定，那么该分区表上所有分区的统计信息就都保持锁定。 +* 如果表或者分区被 truncate，该表或分区上的统计信息锁定将会被解除。 + +具体行为参见下面表格： + +| | 删除整张表 | Truncate 整张表 | Truncate 某个分区 | 创建一个新分区 | 删除某个分区 | Reorganize 某个分区 | 交换某个分区 | +|----------------------------|------------|----------------------------------------------------------------|----------------------------------------------------------------|----------------|----------------------------------------------|----------------------------------------------|--------------------------| +| 非分区表被锁定 | 锁定失效 | 锁定失效，因为 TiDB 删除了旧表，所以锁定信息也一起被删除 | / | / | / | / | / | +| 分区表并且整张表被锁定 | 锁定失效 | 锁定失效，因为 TiDB 删除了旧表，所以锁定信息也一起被删除 | 旧的分区锁定信息失效，自动锁定新的分区 | 自动锁定新分区 | 被删除的分区锁定信息被清理，整张表锁继续生效 | 被删除的分区锁定信息被清理，新分区被自动锁定 | 锁定信息被转移到被交换表，新分区被自动锁定 | +| 分区表并且只锁定了某些分区 | 锁定失效 | 锁定失效，因为 TiDB 删除了旧的分区表，所以锁定信息也一起被删除 | 锁定失效，因为 TiDB 删除了旧的分区表，所以锁定信息也一起被删除 | / | 被删除的分区锁定信息被清理 | 被删除的分区锁定信息被清理 | 锁定信息被转移到被交换表 | + ## 另请参阅 * [LOAD STATS](/sql-statements/sql-statement-load-stats.md)