MySQL 死锁场景

SESSION 1	SESSION 2	SESSION 3
START TRANSACTION	START TRANSACTION	START TRANSACTION
INSERT
	INSERT
		INSERT
ROLLBACK
		Deadlock

解决方案：无解决方案

 

SESSION 1	SESSION 2
START TRANSACTION	START TRANSACTION
SELECT FOR UPDATE
	SELECT FOR UPDATE
INSERT
	INSERT
	Deadlock

解决方案：移除 SELECT FOR UPDATE，改为扑捉 INSERT 的主键冲突的错误。

 

SESSION 1	SESSION 2
START TRANSACTION	START TRANSACTION
DELTE WHERE a
	DELTE WHERE a
INSERT VALUES(a)
	INSERT VALUES(a)
	Deadlock

解决方案：先判断是否存在，存在时更新，不存在时插入

 

SESSION 1	SESSION 2	SESSION 3
START TRANSACTION	START TRANSACTION
INSERT
	INSERT
		INSERT
COMMIT
	SELECT FOR UPDATE
		SELECT FOR UPDATE
		Deadlock

解决方案：将SELECT FOR UPDATE 改为 SELECT LOCK IN SHARE MODE

 

SESSION 1	SESSION 2
START TRANSACTION	START TRANSACTION
UPDATE a
	UPDATE b
UPDATE b
	UPDATE a
	Deadlock

解决方案：请保持写表顺序一致-=