OCP-052考试题库汇总(20)-CUUG内部解答版

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OCP-052考试题库汇总(20)-CUUG内部解答版

bjcuug 2019-08-05 11:27:45 浏览4205
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Which two are true about LGWR?

A)LGWR always writes to the redo logs each time a COMMIT occurs.

B)LGWR always writes to the redo logs each time a ROLLBACK occurs.

C)LGWR never writes a single COMMIT to the redo logs.

D)LGWR may write to the redo logs when DBWR writes a dirty buffer.

E)Multiple COMMITs can be written by LGWR in the same write request.

F)LGWR always writes to the redo logs when DBWR writes a dirty buffer.

Answer: DE

赵:AF=>DE

冉:

DE 两个答案更妥,D 比 F 要好,因为 D 答案用了 may 没有用 always

E 答案给的是 group commit 的概念,即在 lgwr 正在执行时,其他会话发生的 commit 可以做为一组,随后一起提交。

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