Oracle Test-King 053

Exam A

QUESTION 1

You are not sure if Flashback Database is enabled.What database column and view can you query to see if the flashback logs are being created in the flash recovery area?

A. Query the initialization parameter FLASHBACK_DATABASE in V$INSTANCE

B. Query the FLASHBACK_ENABLED cloumn in V$DATABASE

C. Query the FLASHBACK column in V$DATABASE.

D. Query the FLASHBACE_ON cloumn in V$DATABASE.

Answer: D

 

Explanation/Referece:

Explanation:

To enable Flashback Database,you use the command ALTER DATABASE FLASHBACK ON. Your database must be in ARCHIVELOG mode,you must have the flash recovery area configured,and you must have DB_FLASHBACK_RETENTION_TARGET set to an appropriate value.

A,B,and C are incorrect because they all specify cloumns that do not exist.

问题：如果你不确定数据库是否启用了闪回，可以查看那些数据库的列或者视图看看数据库闪回恢复区中有在create flashback logs.

开启数据库 闪回，使用命令：alter database flashback on, 条件是：1、数据库必须是 ARCHIVELOG 模式；2、必须有闪回恢复区；3、DB_FLASHBACK_RETENTION_TARGET 必须配置正确的值。

 

自己看这题库写的，欢迎各位拍砖。