ocp考试资料群：569933648 验证码：ocp OCP 12c 19c考试题库解析与资料群：钉钉群号：35277291
全部博文（487）
分类： Oracle
2019-08-05 11:27:14
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。
