052-30

In which situation may the UNDO_RETENTION parameter be ignored, even if it is set to a value?
A. When the data file of the undo tablespace is autoextensible
B. When there are more than one undo tablespace available in the database
C. When the undo tablespace is of a fixed size and retention guarantee is not enabled
D. When the undo tablespace is autoextensible and retention guarantee is not enabled

  此题考的是 UNDO_RETENTION 即使设置了值,在哪些情况下会忽略。
  在固定大小的还原表空间,且没有设置 retention guarantee 强制保留,UNDO_RETENTION 就会被忽略。如果设置了 retention guarantee ,即使是固定大小的表空间,也不会忽略 UNDO_RETENTION,但有可能出现事务失败。

posted @ 2017-12-05 14:48  巴啦啦大魔王  阅读(98)  评论(0编辑  收藏  举报