On Fri, 3 Oct 2003, Richard Huxton wrote:
> On Thursday 02 October 2003 19:55, Network Administrator wrote:
> > Quoting Richard Huxton <dev@archonet.com>:
> > > [stuff deleted]
> > >
> > > Stability is good. If you're feeling cautious, you could use 7.3.4 rather
> > > than
> > > the forthcoming 7.4. It's had hot-backup (i.e. no need to stop the db to
> > > get
> > >
> > > a valid snapshot) for ages. It has a write-ahead-log to replay active
> > > transactions in case of a crash, and a couple of replication options.
>
> > Is the ability to do "hot-backups" removed from 7.4.x? I haven't read the
> > all of the beta3 docs yet.
>
> As Bruno says - no (and I can't imagine why anyone would).
>
> I was merely suggesting the fact that the 7.3 series is at it's fourth minor
> revision means it's received a lot more testing, whereas 7.4.0 still has the
> paint wet on it.
>
>
Hot backup? Postgres 7.3 can't really do hot-backup! The only way
to backup the database is to dump the entire thing. Two minites later this
backup is only news and not exactly hot. Having to shut your database down
to back it up would be down right nasty! But Since we don't yet have an
update log. Even a dump will not get you back to the good point before
your disk died.
Mind you the truth is the downdate log should work for most cases.
So take regualar backups... and use raid. I mean how often does an entire
raid array fail at once?
I would love to see an Update Log on postgres. That and true
replications (dual master) are the two biggest missing features in
Postgres. If we had them we could run circles round mysql and oracle as
well.
Its not as if an update log is a new idea. Our old system (that we
are replacing with postgres) has an update log. So you can always get from
the last backup to now using it. (Its a TPS Bull System) The update logs
last about 2 weeks if we forget to backup! (Since we have to shutdown to
backup we only do a full backup once a week) but apparently we have never
had to use the update logs in 9 years......
Maybe it would be a good idea to start a mailinglist marked
pgsql-backup since this subject comes up so often.
Peter Childs
