（700）Which two statements are true about a duplicate database that is created by using the DUPLICATE command in RMAN?(Choose two.)

A. It is a copy or a subset of the target database.

B. It is opened in RESTRICT mode after a duplicating operation.

C. It is created by using backups and archived redo log files from the target database.

D. It is created with the same database identifier(DBID)as that of target database.

答案：（A、C）

解析：

A，duplicate是从backup中恢复一个数据库到另外地方，而恢复出来的数据库也成为一个copy或者一个子集合，也就是以后恢复时也会成为一个可用的数据源。

C，讲得是从当前的备份中恢复数据库然后加上归档日志，新的数据库有一个唯一的dbid

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Oracle 11G OCP 1Z0-053 700