Oracle 有三种常见的死锁:
1)ORA-60, enqueue deadlocks;
2)ORA-4020, library cache deadlocks;
3)Deadlocks in RAC
一、ORA-60, enqueue deadlocks
这种死锁很容易重现，按照如下步骤操作：
In sessionA, update tb set col = ‘x’ where pk = ‘aa’
In sessionB, update tb set col = ‘x’ where pk = ‘bb’
In sessionA, update tb set col = ‘x’ where pk = ‘bb’
In sessionB, update tb set col = ‘x’ where pk = ‘aa’