mysql deadlock

transaction isolation

1. RU(read uncommitted)

2. RC(read committed)

3. RR(repeatable read)

4. Serializable

 

 

mysql提供了两种读取方式：快照度(snapshot read)和当前读(current read)

 

current read包含三种情况：

1. select ... lock in share mode   加S锁

2. select ... for update 加X锁

3. insert,update,delete 加X锁