（620）You are using the control file to maintain information about the database backups that are being performed by Recovery Manager(RMAN).

Identify two scenarios is which you must have a recovery catalog.(Choose two.)

A. To store the backup information of multiple database

B. To restrict the amount of space that is used by the backups

C. To maintain a backup for a certain time is set by the CONTROL_FILE_RECORD_KEEP_TIME parameter.

D. To list the data files that were in a target database at a given time by using the AT option of REPORT SCHEMA command.

答案：（A、D）

解析：

A，catalog数据库目的就是存放rman备份的元数据，所以有多个数据库的rman元数据需要管理的话，可以存放在一台服务器上，实现集中管理

D，执行REPORT SCHEMA…AT命令的时候，必须要有CATALOG数据库

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Oracle 11G OCP 1Z0-053 620