You are managing an Oracle Database 11g database with the following backup strategy: 1.
On Sunday, an incremental level 0 tape backup is performed 2. Monday through Saturday,
a cumulative incremental level 1 tape backup is performed Which two statements are true
regarding the backups performed? (Choose two.)
A.
The backup performed in step 1 backs up all the blocks changed since the most recent
level 1 backup
B.
The backup performed in step 2 copies all the blocks changed since the most recent
level 0 backup
C.
The backup performed in step 1 backs up all blocks that have ever been in use in the
database
D.
The backup performed in step 2 backs up all blocks that have changed since the most
recent incremental backup at level 1
Answer: B, C
http://docs.oracle.com/cd/E25054_01/backup.1111/e10642/rcmcncpt.htm
Incremental Backups
By default, RMAN makes full backups. A full backup of a datafile includes every allocated block in the file being backed up. A full backup of a datafile can be an image copy, in which case every data block is backed up. It can also be stored in a backup set, in which case datafile blocks not in use may be skipped.
A full backup is the default type of RMAN backup. A full backup has no effect on subsequent incremental backups and is not considered a part of an incremental backup strategy. Image copies are always full backups because they include every data block in a datafile. A backup set is by default a full backup because it can potentially include every data block in a datafile, although unused block compression means that blocks never used are excluded and, in some cases, currently unused blocks are excluded (see “Block Compression for Backup Sets”).
In contrast to a full backup, an incremental backup copies only those data blocks that have changed since a previous backup. You can use RMAN to create incremental backups of datafiles, tablespaces, or the whole database. A full backup cannot be part of an incremental backup strategy; that is, it cannot be the parent for a subsequent incremental backup.
Multilevel Incremental Backups
RMAN can create multilevel incremental backups. Each incremental level is denoted by a value of 0 or 1. A level 0 incremental backup, which is the base for subsequent incremental backups, copies all blocks containing data. You can create a level 0 database backup as backup sets or image copies.
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. Thus, an incremental level 0 backup is a full backup that happens to be the parent of incremental backups whose level is greater than 0.
A level 1 incremental backup can be either of the following types:
•A differential incremental backup, which backs up all blocks changed after the most recent incremental backup at level 1 or 0
•A cumulative incremental backup, which backs up all blocks changed after the most recent incremental backup at level 0
Incremental backups are differential by default.