Monday, June 13, 2011

RMAN is not removing my logs, why?

I'm not going to go into the details and various scenarios of RMAN and archive logs not being removed. The purpose of this entry is (other than a filler) to provide a head's up, if you will, as to what you are likely to encounter now in an 11g environment using RMAN and GoldenGate (or Streams). I've made mention in my prior post on the relationship between GoldenGate and Streams here.

So it seems that again, due to our usage of GoldenGate, that Streams is also being enabled under the covers. It seems also that there is a 6 hour delay in archive logs being removed via RMAN even if they are not required! Once again, doing the requisite research, we found that this is actually expected behavior. RMAN is looking at the MIN_REQUIRED_CAPTURE_CHANGE# in v$database and not at DBA_CAPTURE which only gets updated every 6 hours. There is a workaround which involves forcefully deleting the archive logs using an RMAN statement similar to:

delete noprompt force archivelog all completed before 'sysdate-10/1440';

I'm not sure why the change in behavior which now leads to this situation but I can't say were too thrilled. Seems like a bug or perhaps not yet fully thought out or completed perhaps? In any case, we've got the backup scripts and everything thought out so no harm, no foul. Moving on with the project...

Oh, you can reference the MOS article: "RMAN-08137 When deleting archivelogs even when Streams CAPTURE does not require them [ID 1079953.1]"