OCP-1Z0-053-V12.02-184题

184.Which RMAN backup command is used to create the block-change tracking file?

A. alter database create block change tracking file

B. alter database enable block change file

C. alter database enable block change tracking using file ,,/ora01/opt/ block_change_tracking.fil

D. alter system enable block change tracking using file '/ora01/opt/block_ change_tracking.fil'

E. alter system block change tracking on

Answer: C

答案解析：

参考：http://blog.youkuaiyun.com/rlhua/article/details/12321679

You can enable block change tracking when the database is either open or mounted.

To enable block change tracking:

1. Start SQL*Plus and connect to a target database with administrator privileges.

2. Ensure that the DB_CREATE_FILE_DEST initialization parameter is set.

   SHOW PARAMETER DB_CREATE_FILE_DEST

   If the parameter is not set, and if the database is open, then you can set the parameter with the following form of the ALTER SYSTEM statement:

   ALTER SYSTEM SET

   DB_CREATE_FILE_DEST = '/disk1/bct/'

   SCOPE=BOTH SID='*';

3. Enable block change tracking.

   Execute the following ALTER DATABASE statement:

   ALTER DATABASE ENABLE BLOCK CHANGE TRACKING;

   You can also create the change tracking file in a location that you choose yourself by using the following form of SQL statement:

   ALTER DATABASE ENABLE BLOCK CHANGE TRACKING

   USING FILE '/mydir/rman_change_track.f' REUSE;

   The REUSE option tells Oracle Database to overwrite any existing block change tracking file with the specified name.

官方参考：http://docs.oracle.com/cd/E16655_01/backup.121/e17630/rcmbckba.htm#BRADV8125