importmysql.connectordefcheck_table_locks(connection):cursor=connection.cursor()# 查询当前锁定的表cursor.execute("SELECT * FROM information_schema.INNODB_LOCKS")locks=cursor.fetchall()forlockinlocks:database_name=lock[2]table_name=lock[3]lock_type=lock[4]lock_holder=lock[5]# 将锁信息插入到lock...
RECORD LOCKS space id 321 page no 13948 n bits 240 index `idx_companygrandsong_songid` of table `kmsong`.`km_tbl_companygrandsong` trx id 309164542 lock_mode X locks gap before rec insert intention waiting Record lock, heap no 134 PHYSICAL RECORD: n_fields 2; compact format; info bits ...
可以通过检查table_locks_waited 和 table_locks_immediate 状态变量分析系统上的表锁定:show status like 'table_locks%' 代码语言:txt 复制 mysql> show status like 'table_locks%'; +---+---+ | Variable_name | Value | +---+---+ | Table_locks_immediate | 104 | | Table_locks_waited | 0...
可以通过查询 sys.schema_table_lock_waits 这张表直接找出造成阻塞的 process id,把这个连接kill命令断开即可 (MySQL启动时需要设置 performance_schema=on,相比于设置为off会有10%左右的性能损失) 方式4:等 flush select*frominformation_schema.processlistwhereid=1; 通过State列,查出来某个线程状态为Waiting for ...
一般情况下,不会使用 InnoDB 存储引擎提供的表级别的 S 锁和 X 锁(因为 InnoDB 支持更小粒度的行锁),只会在一些特殊情况下,比方说崩溃恢复过程中用到。比如,在系统变量 autocommit=0,innodb_table_locks = 1 时,手动获取 InnoDB 存储引擎提供的表 t 的 S 锁或者 X 锁,可以这么写: ...
mysql>use information_schema;Reading table informationforcompletionoftable and column names You can turn offthisfeature togeta quicker startupwith-ADatabase changed mysql>show tables;+---+|Tables_in_information_schema|+---+|ADMINISTRABLE_ROLE_AUTHORIZATIONS||APPLICABLE_ROLES||CHARACTER_SETS||CHECK...
enable_warnings CREATE TABLE t ( i INT ); --echo # One connection locks the table LOCK TABLE t WRITE; --connect (con1,localhost,root,,) SET lock_wait_timeout=1; --echo # Another connection is trying to run CHECK CHECK TABLE t; --connection default UNLOCK TABLES; DROP TABLE t; -...
We do not set InnoDB table locks if user has not explicitly requested a table lock. Note that thd_in_lock_tables(thd) can hold in some cases, e.g., at the start of a stored procedure call (SQLCOM_CALL). */ if (m_prebuilt->select_lock_type != LOCK_NONE) { ...
Each table is locked and therefore unavailable to other sessions while it is being processed, although for check operations, the table is locked with aREADlock only (seeSection 15.3.6, “LOCK TABLES and UNLOCK TABLES Statements”, for more information aboutREADandWRITElocks). Table maintenance ope...
Themysqlcheckclient performs table maintenance: It checks, repairs, optimizes, or analyzes tables. Each table is locked and therefore unavailable to other sessions while it is being processed, although for check operations, the table is locked with aREADlock only (seeSection 13.3.5, “LOCK TABL...