206  Chapter 4  n  Configuring and Backing Up Using RMAN

Answers to Review Questions

1.A.  Block-change tracking must be enabled with alter database enable block change tracking. The physical location and name of the block-change tracking file must be supplied.

2.A.  The backup set is stored in a proprietary RMAN format, where only used blocks are backed up.

3.D.  The following backup sets would be created:

NNOne for the main backup. Since we are using a single channel with no backup-set size restriction, RMAN would create a single backup set.

NN One for the control-file autobackup.

4.A.  The backup as copy command is used to create an image-copy backup.

5.C.  Compressed backups work only with backup sets, not image copies. Thus, compressed backups will work only with the backup command.

6.D.  The correct answer is to use the backup database plus archivelog delete input command.

7.D.  A full backup is best described by backing up all the used blocks in a datafile or any database file. A full backup can be taken on one database file.

8.A.  A differential incremental backup backs up only blocks that have been modified since a backup at the same level or lower.

9.B.  A level-0 backup is the first backup that is performed when implementing an incremental backup strategy. A level-0 backup copies all the used blocks as a baseline.

10.C.  The TAG option is used to name a backup with a user-defined character string.

11.E.  The correct order of operations is to log into RMAN and then shut down the database with the shutdown immediate command. You then mount the database with the startup mount command. Once the database is mounted, you back up the database with the backup database command. Finally, after the backup is complete, you open the database.

12.D.  Image copies are similar to operating-system copy commands. These equate to bit-by-bit copies of a file.

13.B.  The V$BLOCK_CHANGE_TRACKING dynamic view shows the filename, status, and size of the block-change tracking file.

14.A.  Channel failover is the RMAN feature that provides the ability for other channels to take over the work of a failed channel during backup and recovery operations. Obviously, channel failover requires the allocation of more than one channel.

15.C.  The command that sets the persistent setting that directs RMAN to back up to tape is

CONFIGURE DEFAULT DEVICE TYPE TO SBT.

16.C, E.  The CONTROL_FILE_RECORD_KEEP_TIME initialization parameter should never be set to 0 if you are using RMAN. If this value is set to 0, there is a potential to lose backup records.

17.A.  Backing up in ARCHIVELOG mode is as easy as issuing the backup database plus archivelog delete input command.

18.B, C.  The BACKUP command can take advantage of multiplexing datafiles to the same backup set. The BACKUP command can also use the block-change tracking capability.

19.C.  Use the CONFIGURE DEVICE TYPE DISK BACKUP TYPE TO COMPRESSED BACKUPSET command to configure RMAN to always create a compressed backup by default.

20.B.  Backup optimization is a feature whereby Oracle will not back up a read-only tablespace as long as that tablespace has been backed up such that it meets the backup retention criteria.