Consider the following scenario for your database:
Backup optimization is enabled in RMAN.
The recovery window is set to seven days in RMAN.
The most recent backup to disk for the tools tablespace was taken on March 1, 2013.
The tools tablespace is read-only since March 2, 2013.
On March 15, 2013, you issue the RMAN command to back up the database to disk.
Which statement is true about the backup of the tools tablespace?
A.
The RMAN backup fails because the tools tablespace is read-only.
B.
RMAN skips the backup of the tools tablespace because backup optimization is enabled.
C.
RMAN creates a backup of the tools tablespace because backup optimization is
applicable only for the backups written to media.
D.
RMAN creates a backup of the tools tablespace because no backup of the tablespace
exists within the seven-day recovery window.
B is wrong. D is the correct answer since the recovery window is set to 7 days. A backup further in the past than the set recovery window will be considered “obsolete”.
D
D
I too feel D
I feel D
probably D but not sure
D
Because backup optimization is configured, RMAN skips backups of offline and read-only data files only if the most recent backups were made on or after the earliest point in the recovery window. RMAN does not skip backups when the most recent backups are older than the window. For example, optimization ensures you do not end up with a new backup of a read-only data file every night, so long as one backup set containing this file exists within the recovery window.
https://docs.oracle.com/database/121/BRADV/rcmbckad.htm#BRADV89548
This is true for device type SBT.
But for Disk as in the question:
For backups to disk, RMAN skips taking the backup if an identical file is available from a backup on disk, even if that backup is older than the beginning of the recovery window. The retention policy causes RMAN to retain the old backup for as long as it is needed.
For backups to tape, RMAN takes another backup of a file, even if a backup of an identical file exists, if the most recent backup is older than the configured recovery window. This is done to allow media to be recycled after the media expires.
https://querycsm.wordpress.com/2013/06/16/backup-optimization-in-rman/
So correct answer is B.
think sisinasan, B is correct
https://docs.oracle.com/database/121/RCMRF/rcmsynta009.htm#GUID-B5094E73-C26C-4FED-AE39-8C2E9540050A__G1028761 (Table 2-3 Backup Optimization Algorithm)
D
D
Clearly at EN_SILVA link:
https://docs.oracle.com/database/121/BRADV/rcmbckad.htm#BRADV89548
B
EN_SILVA your reference is IMHO not valid because it concerns backup to tape, not to disk.
For backups to disk, RMAN skips the backup if an identical data file is available on disk, even if that backup is older than the beginning of the recovery window. The window-based retention policy causes RMAN to retain the old backup if it is needed.
http://www.dba-oracle.com/t_rman_tuning.htm
Setting backup optimization on stops the backups of Read Only Tablespaces (ROT), whenever a valid backup of the tablespace already exists in the RMAN catalog database.
D