Re: Implementing incremental backup

* Tatsuo Ishii (ishii(at)postgresql(dot)org) wrote:
> > * Tatsuo Ishii (ishii(at)postgresql(dot)org) wrote:
> >> Yeah, at first I thought using WAL was a good idea. However I realized
> >> that the problem using WAL is we cannot backup unlogged tables because
> >> they are not written to WAL.
> >
> > Unlogged tables are also nuked on recovery, so I'm not sure why you
> > think an incremental backup would help.. If you're recovering (even
> > from a simple crash), unlogged tables are going to go away.
>
> If my memory serves, unlogged tables are not nuked when PostgeSQL is
> stopped by a planned shutdown (not by crash or by "pg_ctl -m i
> stop"). If PostgreSQL works so, incremental backup should be able to
> recover unlogged tables as well, at least people would expect so IMO.

Sure, if you shut down PG, rsync the entire thing and then bring it back
up then unlogged tables should work when "backed up".

They're not WAL'd, so expecting them to work when restoring a backup of
a PG that had been running at the time of the backup is folly.

Thanks,

Stephen