Managing RMAN Backup Window Load and Duration

Duration in RMAN

DURATION Clause used to complete the RMAN backup in that particular duration. If it’s not complete in that specific time then old backup is retained and new backup is discarded.

BACKUP DURATION 4:00 PARTIAL TABLESPACE users FILESPERSET 1;

PARTIAL is used with Duration to overcome the interrupted caused due to incomplete in time duration during RMAN backup.
In RUN{…} windows then after 4 hours if rman backup is not completed then it’s interrupted and stop all other commands.
To overcome this PARTIAL is used which make possible to run all other commands present in RUN{..} statements.

MINIMIZE TIME and MINIMIZE LOAD

You can run the RUN backup as fast or low dependent upon the duration you specify in DURATION CLAUSE.

To maximize performance, use the MINIMIZE TIME option with DURATION:

BACKUP DURATION 4:00 PARTIAL MINIMIZE TIME DATABASE FILESPERSET 1;

To utilize the full time present in duration clause,

BACKUP DURATION 4:00 PARTIAL MINIMIZE LOAD DATABASE FILESPERSET 1;

Note: RMAN estimate that the backup will finish before the end of the backup window then it slows down the rate of backup so it will utilize the complete window of duration.
Benefit: This reduces the overhead on the database.