On Fri, Dec 01, 2000 at 10:01:15AM +0100, Zeugswetter Andreas SB wrote:
>
> > > > No, WAL does help, cause you can then pull in your last dump and recover
> > > > up to the moment that power cable was pulled out of the wall ...
> > >
> > > False, on so many counts I can't list them all.
> >
> > would love to hear them ... I'm always opening to having my
> > misunderstandings corrected ...
>
> Only what has been transferred off site can be considered safe.
> But: all the WAL improvements serve to reduce the probability that
> you 1. need to restore and 2. need to restore from offsite backups.
>
> If you need to restore from offsite backup you loose transactions
> unless you transfer the WAL synchronously with every commit.
Currently the only way to avoid losing those transactions is by
replicating transactions at the application layer. That is, the
application talks to two different database instances, and enters
transactions into both. That's pretty hard to retrofit into an
existing application, so you'd really rather have replication in
the database. Of course, that's something PostgreSQL, Inc. is also
working on.
Nathan Myers
ncm@zembu.com
