LOCK=DEFAULT:默认方式,MySQL自行判断使用哪种LOCK模式,尽量不锁表 LOCK=NONE:无锁:允许Online DDL期间进行并发读写操作。如果Online DDL操 作不支持对表的继续写入,则DDL操作失败,对表修改无效 LOCK=SHARED:共享锁:Online DDL操作期间堵塞写入,不影响读取 LOCK=EXCLUSIVE:排它锁:Online DDL操作期间不允许对锁表进行...
其实早在 MySQL 5.5 版本中就加入了 INPLACE DDL 方式，但是因为实现的问题，依然会阻塞 INSERT、UPDA...
当出现问题时没能力第一时间解决问题，出现问题后不去层层剖析问题产生的原因，后续也就可能无法避免或者...
Operations avoid copying table data but may rebuild the table in place. An exclusive metadata lock on the table may be taken briefly during preparation and execution phases of the operation. Typically, concurrent DML is supported. 1 ALGORITHM = COPY Operations are performed on a copy of the ori...
Description: Creating a functional index using the syntax: ALTER TABLE mytable ADD INDEX n12((concat(`n1`, `n2`)), ALGORITHM=INPLACE, LOCK=SHARED; generates the following error: 1846 - ALGORITHM=INPLACE is not supported. Reason: INPLACE ADD or DROP of virtual columns cannot be combined wi...
InnoDB supports modifying a column's DEFAULT value with ALGORITHM set to INPLACE. This operation only changes the table's metadata, so the table does not have to be rebuilt. This operation supports the non-locking strategy. This strategy can be explicitly chosen by setting the LOCK clause to...
"Object is currently in use elsewhere" error for picturebox "Parameter is not valid" - new Bitmap() "Recursive write lock acquisitions not allowed in this mode.? "Settings" in DLL project properties and app.config file "The function evaluation requires all threads to run" while accessing mus...
创建索引结束ALGORITHM=COPY通过临时表创建索引,需要多一倍存储,还有更多的IO,步骤:1.新建带索引(主键索引)的临时表2.锁原表,禁止DML,允许查询3.将原表数据拷贝到临时表4.禁止读写,进行rename,升级字典锁5.完成创建索引操作LOCK=DEFAULT:默认方式,MySQL自行判断使用哪种LOCK模式,尽量不锁表LOCK=NONE:无锁:允许...
Can I prevent deadlock during concurrent delete Can I print to file using T- SQL Can I sort an SQL table? Can I sort row without order by clause Can I UPDATE, then INSERT if no record updated? Can I use a COLLATE clause in a temp table definition? Can I use aggregate function with...
ALTERTABLEtbl_nameADDPRIMARYKEY(column),ALGORITHM=INPLACE,LOCK=NONE; ALGORITHM是用表示执行DDL的算法;其中,LOCK语句是用来控制DML/DQL等访问表的并发度,后面会详细介绍。 2. ALGORITHM语句和LOCK语句 2.1 ALGORITHM语句 对于ALGORITHM语句,InnoDB提供了以下两个方式: 1)ALGORITHM=INPLACE 在执行DDL时不进行复制,而是...