马克.吐温是（)作家。A．法国B．英国C．德国D．美国

A. The backup as copy can only be taken to disk

B. The backup as copy can only be taken to tape

C. Backup can be performed only when the instance is shutdown

D. Backup will constitute all used and unused blocks in the database

EVER option. After some days, you want to change the status of the database backup and you issued the following command:RMAN>CHANGE BACKUPSET 231 NOKEEP;What is the implication of this command？（）

A. The backup is deleted.

B. The backup is marked unavailable.

C. The backup overrides the backup retention policy.

D. the backup becomes eligible for deletion according to the existing retention policy

A. A different procedure is required to restore a database from compressed backups

B. The AS COMPRESSED clause of the BACKUP command provided by RMAN is used to create compressed backup sets and image copies.

C. Using this command to create backups minimizes the bandwidth consumed

D. Using this command to create backups improves the performance of the backup process

Your multitenant container database (CDB) contains a pluggable database, HR_PDB. The default permanent tablespace in HR_PDB is USERDATA. The container database (CDB) is open and you connect RMAN.You want to issue the following RMAN command:RMAN > BACKUP TABLESPACE hr_pdb:userdata;Which task should you perform before issuing the command？（）

A. Place the root container in ARHCHIVELOG mode.

B. Take the user data tablespace offline.

C. Place the root container in the nomount stage.

D. Ensure that HR_PDB is open.

EL 0 DATABASE;To enable block change tracking after the incremental level 0 backup, you issued this command:SQL > ALTER DATABASE ENABLE BLOCK CHANGE TRACKING USING FILE ‘ /mydir/rman_change_track.f’;To perform an incremental level 1 cumulative backup, you issued this command:RMAN> BACKUP INCREMENTAL LEVEL 1 CUMULATIVE DATABASE;Which three statements are true？（）

A. Backup change tracking will sometimes reduce I/O performed during cumulative incremental backups.

B. The change tracking file must always be backed up when you perform a full database backup.

C. Block change tracking will always reduce I/O performed during cumulative incremental backups.

D. More than one database block may be read by an incremental backup for a change made to a single block.

E. The incremental level 1 backup that immediately follows the enabling of block change tracking will not read the change tracking file to discover changed blocks.

You have tape drives of 300 MB each. The SBT channel is configured for Recovery Manager (RMAN).To accomplish the backup, you issued the following RMAN command:RMAN> BACKUP SECTION SIZE 300M TABLESPACE users;Which two statements are true about the execution of the above command？ （）(Choose two.)

A. The backup piece size will be limited to 300 MB

B. The RMAN uses multiplexing to perform backup

C. The operation is accomplished using the default channel available

D. The RMAN parallelizes the backup although the parallelism is not set for a channel

You are using recovery Manager (RMAN) with a recovery catalog to backup up your production database. The backups and the archived redo log files are copied to a tape drive on a daily basis. The database was open and transactions were recorded in the redo logs. Because of fire in the building you lost your servers having the production database and the recovery catalog database.The archive log files generated after the last backup are intact on one of the remote locations.While performing a disaster recovery of the production database what is the next step that you must perform after restoring the data files and applying archived redo logs？（）

A. Open the database in NORMAL mode

B. Open the database in read-only mode

C. Open the database in RESTRICTED mode

D. Open the database with the RESETLOGS option

You are using recovery Manager (RMAN) with a recovery catalog to backup up your production database. The backups and the archived redo log files are copied to a tape drive on a daily basis. The database was open and transactions were recorded in the redo logs. Because of fire in the building you lost your servers having the production database and the recovery catalog database.The archive log files generated after the last backup are intact on one of the remote locations. While performing a disaster recovery of the production database what is the next step that you must perform after restoring the data files and applying archived redo logs？（）

A. Open the database in NORMAL mode

B. Open the database in read-only mode

C. Open the database in RESTRICTED mode

D. Open the database with the RESETLOGS option