OCP-1Z0-053-V12.02-584题

584.How is block-change tracking enabled?

A. With alter database enable block change tracking

B. With alter system enable block change tracking

C. With an init.ora parameter change

D. With an spfile parameter change

Answer: A

答案解析：

参考：/article/1629017.html

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

To enable block change tracking:

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

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='*';

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