On 2/16/07,
Andy Shellam (Mailing Lists) <
andy.shellam-lists@mailnetwork.co.uk> wrote:
Why bother trying to delete WAL files older than the .backup file? When PostgreSQL is in recovery mode it knows which WAL files are necessary to perform the recovery.
Also, the documentation recommends excluding the pg_xlog directory when performing the base backup. Likely when it comes time to recovery the online WAL files have been archived already, so it is a risk of confusion I am sure.
If the OP is doing the same as myself, the WAL files are being archived outside of pg_xlog (indeed outside of the PG data cluster) - it makes no sense keeping around WAL files older than the .backup file because they're not needed - in a day I generate ~5GB worth of WAL files which aren't needed after the full backup runs at 2am, so it's a waste of resources to keep them around or to worry about backing them up after this time.
I mentioned this in my other response, the only reason I ask is because of the potential need to recover from an earlier base backup up to a specific point -- perhaps before the most recent base backup. Personally I don't think it is a good idea for every environment to do this, but I can see the value in it and if you truly feel it is unnecessary then I can certainly respect that. Perhaps I am a bit too paranoid :), but I have seen people foolishly do a huge cleanup and then take a backup and realize "Oh crap, I did too much!" -- and if you don't have all the WAL files you certainly can't guarantee a specific PITR.
--
Chad
http://www.postgresqlforums.com/