对于介质故障的恢复有两步,第一步装入后备副本文件(如果是动态转储的后备数据还需要同时装入转储时刻的日志文件),第二部装入转出结束时的日志文件,进行已完成事务的重做。
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如果一个调度的结果与某一串行调度执行的结果等价,则称该调度是可串行化调度。()
A. 对
B. 错
可串行化的含义:每个事务中,语句的先后顺序在各种调度中始终保持一致,在这个前提下,如果一个并发调度的执行结果与某一串行调度的执行结果等价,那么这个并发调度称为可串行化的调度。否则是不可串行化的调度。
A. 对
B. 错
Section A Directions: This section is to test your ability to understand short dialogues.
A. The winter has just begun.
B. Once it starts, it'll snow a lot.
C. They're ready for the rain.
D. It has been raining for some time.
Directions: This section is to test your ability to understand short dialogues.
A. Mike was not able to go skiing.
B. Mike will go skiing next week.
C. Mike broke his leg and caught a cold.
D. It was too cold for Mike to go skiing.