Re: WAL files backup

Chad Wagner wrote:
> On 2/15/07, *Eduardo J. Ortega* <ejortegau(at)cable(dot)net(dot)co
> <mailto:ejortegau(at)cable(dot)net(dot)co>> wrote:
>
> After erasing the "less than names" WAL files, we add to tar the
> remaining
> WAL records (0003B, 0003C and so on on the example). The more WAL
> files you
> have after 0003B, the more up to date DB you get after restore
> (since it has
> more WAL files indicating more transactions that took place after
> the backup.
>
>
> 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 recovery the online WAL files have been archived already, so it is a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.

Andy.