已知事务 T1 的封锁序列为:LOCK S（A)...LOCK S（B)...LOCK X（C) ...UNLOCK（B) ...UNLOCK （A) ...UNLOCK （C) 事务 T2 的封锁序列为:LOCK S（A) ...UNLOCK （A) ...LOCK S（B) ...LOCK X（C) ...UNLOCK （C) ...UNLOCK （B) 则遵守两段封锁协议的事务是A．T1B．T2C．T1和T2D．没有
已知事务 T1 的封锁序列为:LOCK S（A)...LOCK S（B)...LOCK X（C) ...UNLOCK（B) ...UNLOCK （A) ...UNLOCK （C) 事务 T2 的封锁序列为:LOCK S（A) ...UNLOCK （A) ...LOCK S（B) ...LOCK X（C) ...UNLOCK （C) ...UNLOCK （B) 则遵守两段封锁协议的事务是
A．T1
B．T2
C．T1和T2
D．没有
参考答案和解析
T1
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