I am somewhat new to RMAN, and have taken an Oracle class on it, but I am stumped on validating my backups when using level 0 and 1; in order to save space, I am considering doing a level 0 (full) incremental backup Sunday, level 1 differential backups Monday and Tuesday, and level 1 cumulative on Wednesday. Then leve1 1 differential backups Thursday and Friday, and level 1 cumulative on Saturday.

The thought was after a successful level 1 cumulative backup on Wednesday, I could delete the differential level 1 backups from Monday and Tuesday. So, on Wednesday, to verify before I do something drastic to test, I did a

RMAN> restore database validate;

And away it went, validating files; but it only looked at files from the level 0 Sunday backup.

I would have expected it to also validate at least the incremental level 1 backup from Wednesday.

So two questions:

  1. Is my strategy of deleting differential level 1 backups after a successful incremental level 1 backup valid?
  2. How can I test to ensure this is correct?

1 Answer 1


First, you need to discover which backup is your level 0 and your 1. Then you need to validate the level 0 and the level 1 backups, independently.


From the list, find the key for your level 0 and your level 1 backups. Then validate them via:


Substitute your key values in that. You can also add in the key values for archive log backups, if any.

See https://docs.oracle.com/cd/B28359_01/backup.111/b28273/rcmsynta053.htm#RCMRF162 Example 2-157 Validating a Backup Set, for more details.

This is beyond the scope of your original question, but may be of benefit to you:

I run RMAN backup configuration scripts as part of my "new Oracle instance" checklist. That script looks like this:

run {
    configure compression algorithm 'MEDIUM' optimize for load false;
    configure device type disk backup type to compressed backupset;
    configure device type disk parallelism 2;  }

Then I do my backups via this, with either a level = 0 or a level = 1, depending on the day of the week:

backup device type disk incremental level = 0 section size 1g database plus archivelog tag 'level 0';
backup current controlfile tag='Controlfile Level 0';
backup spfile tag='SPFile Level 0';

I then do the following. Probably not necessary, but...

allocate channel for maintenance type disk;
backup validate check logical database archivelog all;

crosscheck archivelog all;
crosscheck backupset ;
crosscheck backup device type disk;
release channel;
  • OK, so I was able to validate my level 0 and my cumulative level 1 backups; but I'm still cloudy whether I can safely delete the differential level 1 backups taken between the level 0 and the cumulative level 1 backup. Is the only way to test is to copy my level 0 and cumulative level 1 backups to a different server and attempt to restore the database instance onto the different server from those files? Commented Jun 22, 2018 at 14:44
  • 1
    If you define a retention policy in RMAN via a command like CONFIGURE RETENTION POLICY TO RECOVERY WINDOW OF 14 DAYS; then RMAN will purge data files that it doesn't need whenever it needs to recover that space.
    – CaM
    Commented Jun 22, 2018 at 15:06
  • 1
    @MarkStewart I just added more detail. It may help you?
    – CaM
    Commented Jun 22, 2018 at 15:27

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