You perform differential incremental level 1 backups of your database on each working day and level
0 backup on Sunday to tape:
Which two statements are true about differential incremental backups? (Choose two.)
A.
The backup performed on Sundays contains all the blocks that have ever been used in the
database
B.
The backup performed on Sundays contains all the blocks that have changed since the last level 1
backup
C.
The backup performed on each working day contains all the blocks that have changed since the
last level 0 backup
D.
The backup performed on Monday contains all the blocks that have changed since the level 0
backup and every other working day contains all the blocks that have changed since the level 1
backup
Incremental backups can be either level 0 or level 1. A level 0 incremental backup, which is the base for subsequent incremental backups, copies all blocks containing data, backing the datafile up into a backup set just as a full backup would. The only difference between a level 0 incremental backup and a full backup is that a full backup is never included in an incremental strategy.
A level 1 incremental backup can be either of the following types:
A differential backup, which backs up all blocks changed after the most recent incremental backup at level 1 or 0
A cumulative backup, which backs up all blocks changed after the most recent incremental backup at level 0
Differential Incremental Backups
In a differential level 1 backup, RMAN backs up all blocks that have changed since the most recent cumulative or differental incremental backup, whether at level 1 or level 0. RMAN determines which level 1 backup occurred most recently and backs up all blocks modified after that backup. If no level 1 is available, RMAN copies all blocks changed since the level 0 backup.
Sundays differential incremental level 0 backup operation, the backup operation to back up the entire database.
According to the level 0 backup, we will start Monday through Saturday level 1 differential incremental backup operations.
Using differential backups, the daily backup will contain all the changes that have occurred since the last differential backup.
Finally, the next Sunday, do not perform a basic backup (ie incremental level 0 backup).
When performing incremental backups, you first need the basic incremental backup (incremental base backup), namely level 0, all future incremental backups are based on this basic backup.
Each time you perform a database backup operation, you can send an incremental backup level identifier through incremental backup command parameters.
Basic backup incremental level 0, and must have a basic backup to be able to perform other types of incremental backup operations.
If you do not try to generate a basic backup to perform an incremental backup (incremental backup operation using the backup level other than 0), RMAN automatically perform basic backup operations.