mysql 表级锁之一lock table 1.lock table t1 read: 1.1.当前线程: 读/写当前表/其他表: unlock tables; locktablet1 read;select*fromt1;INSERTINTO`t1` (`c2`, `c3`, `c4`)VALUES('1','1','1');select*fromt2;INSERTINTO`t2` (`c2`, `c3`, `c4`)VALUES('1','1','1'); 结果: 结论...
mysql>createtabletest( idint,namevarchar(12));Query OK, 0rowsaffected (0.07 sec)mysql>insertintotest->select10001,'kerry'unionall->select10002,'richard'unionall->select10003,'jimmy';Query OK, 3rowsaffected (0.05 sec)Records: 3 Duplicates: 0 Warnings: 0mysql> 1. 2. 3. 4. 5. 6. 7....
Re: Lock table in MySQL 1920 Rick James September 06, 2010 09:51PM Re: Lock table in MySQL 2024 DBA Lead September 06, 2010 10:26PM Re: Lock table in MySQL 2202 Rick James September 07, 2010 10:34PM Sorry, you can't reply to this topic. It has been closed. ...
如上截图,执行mysqldump命令的时候,使用show open tables where in_use >0命令,你会看到MyDB里面的所有表的In_use的值都为1,意味着是当执行mysqldump命令时,是一次性锁定当前库的所有表。而不是锁定当前导出表。 In_use The number of table locks or lock requests there are for the table. For example, ...
mysql>LOCKTABLEtREAD;mysql>SELECT*FROMtASmyalias;ERROR 1100:Table 'myalias' was not locked with LOCK TABLES Conversely, if you lock a table using an alias, you must refer to it in your statements using that alias: mysql>LOCKTABLEtASmyaliasREAD;mysql>SELECT*FROMt;ERROR 1100:Table 't' was...
mysql> LOCK TABLE t READ; mysql> SELECT * FROM t AS myalias; ERROR 1100: Table 'myalias' was not locked with LOCK TABLES Conversely, if you lock a table using an alias, you must refer to it in your statements using that alias: mysql> LOCK TABLE t AS myalias READ; mysql> SELECT...
mysql> showopentableswherein_use >0;+---+---+---+---+|Database|Table| In_use | Name_locked |+---+---+---+---+| MyDB | AO_60DB71_VERSION | 1 | 0 || MyDB | AO_AEFED0_TEAM_TO_MEMBER | 1 | 0 || MyDB | AO_4B00E6_STASH_SETTINGS | 1 | 0 || MyDB | AO_...
今天我们要给大家揭秘一个MySQL数据库里可能发生的“交通堵塞”现象——MDL LOCK堵塞。我们来一探究竟! 1案发现场LOCK TABLE READVSINSERT INTO 案例大概的截图如下: (点击可放大查看) 这里是测试出来的,线上当时也是一个lock table read的语句和一大批insert into的语句被堵塞,当然要恢复很简单,我们可以通过2种方...
MySQL有三种锁的级别:页级、表级、行级。 MyISAM和MEMORY存储引擎采用的是表级锁(table-level locking);BDB存储引擎采用的是页面锁(page-level locking),但也支持表级锁;InnoDB存储引擎既支持行级锁(row-level locking),也支持表级锁,但默认情况下是采用行级锁。
I am locking a table in mysql database by using: LOCK TABLE quantity WRITE; Even after locking it, I am able to insert data from mysql insert prompt and from my php application as well. Please correct me if I have done something wrong. ...