START TRANSACTION命令开启的事务在执行期间可能会受到其他并发事务的影响,而START TRANSACTION WITH CONSISTENT SNAPSHOT命令则通过创建一致性快照,在事务执行期间保持数据的一致性,避免了并发问题的影响。因此,如果需要读取一致的数据视图,可以选择使用START TRANSACTION WITH CONSISTENT SNAPSHOT命令开启事务,这也说明了mysqldum...
1)start transaction 时,是第一条语句的执行时间点,就是事务开始的时间点,第一条select语句建立一致性读的snapshot; 2)start transaction with consistent snapshot 时,则是立即建立本事务的一致性读snapshot,当然也开始事务了;
1)start transaction 时,是第一条语句的执行时间点,就是事务开始的时间点,第一条select语句建立一致性读的snapshot; 2)start transaction with consistent snapshot 时,则是立即建立本事务的一致性读snapshot,当然也开始事务了;
START TRANSACTION是在第一条select执行完后,才得到事务的一致性快照。而START TRANSACTION with consistent snapshot则是立即得到事务的一致性快照。
The statement returns the binlog coordinates pointing at the snapshot. MariaDB (and Percona Server) support extension to the regular STARTTRANSACTIONWITHCONSISTENTSNAPSHOT; syntax as documented inEnhancements for START TRANSACTION WITH CONSISTENT SNAPSHOT. ...
With the introduction of group commit, MariaDB also introduced an enhanced storage engine API for COMMIT that allows engines to coordinate commit ordering and visibility with each other and with the binary log. With these improvements, the START TRANSACTION WITH CONSISTENT SNAPSHOT statement was enhan...
You can also begin a transaction like this: START TRANSACTION WITH CONSISTENT SNAPSHOT; TheWITHCONSISTENT SNAPSHOToption starts a consistent read for storage engines that are capable of it. This applies only toInnoDB. The effect is the same as issuing aSTART TRANSACTIONfollowed by aSELECTfrom any...
START TRANSACTION 允许多个修饰符控制事务特征。要指定多个修饰符,请用逗号分隔它们。● WITH CONSISTENT SNAPSHOT修饰符为支持一致性读取的存储引擎启动一致性读取。这只适用于InnoDB。其效果与发出START TRANSACTION指令,然后从任何InnoDB表中执行SELECT一样。WITH CONSISTENT SNAPSHOT修饰符不会更改当前事务隔离级别,因此...
START TRANSACTION 语句与 MySQL 不完全兼容。 START TRANSACTION 相当于 MySQL 的 START TRANSACTION WITH CONSISTENT SNAPSHOT,即 START TRANSACTION 后执行了一个从 InnoDB 任意表读数据的 SELECT 语句(非 SELECT FOR UPDATE)。 READ ONLY 及其扩展选项都都只是语法兼容,其效果等同于 START TRANSACTION。
Bug #7849START TRANSACTION WITH CONSISTENT SNAPSHOT does not work if wrong isolat level Submitted:12 Jan 2005 23:15Modified:12 Jan 2005 23:30 Reporter:Guilhem BichotEmail Updates: Status:Not a BugImpact on me: None Category:MySQL ServerSeverity:S3 (Non-critical) ...