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任何操作...
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...
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绕开同类的问题。
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...
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...
This strategy can be explicitly chosen by setting the LOCK clause to NONE. When this strategy is used, all concurrent DML is permitted. For example: CREATE OR REPLACE TABLE tab ( a int PRIMARY KEY, b varchar(50) ); SET SESSION alter_algorithm='INPLACE'; ALTER TABLE tab ADD COLUMN c ...
"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...
ExclusiveLockType ExecutionInput ExpandOption ExportTestCaseParams ExpressionFilter ExpressionFilterClause ExpressionFilterGroup ExpressionFilterModel ExpressionValidationItem 拡張機能 拡張機能 ExtensionAcquisitionRequest ExtensionAcquisitionRequest ExtensionAuditLog ExtensionAuditLogEntry ExtensionAuthorization ExtensionBadge ...
(2022) improved the traditional ACO in terms of both pheromone updates and heuristic functions, providing a strategy for solving the deadlock problem. Combined with other methods, ACO is featured by strong robustness, fast optimization search, and strong convergence. Although these fusion strategies ...
This dynamic knowledge is typically structured into elementary events like “The robot sends a message to John” or “John must lock the front door” (see the example). We will refer to this highly dynamic and in fieri knowledge as the foreground knowledge. The overall model will include, ...