Re: unlogged tables

On Tuesday 16 November 2010 23:30:29 Andres Freund wrote:
> On Tuesday 16 November 2010 23:12:10 Josh Berkus wrote:
> > On 11/16/10 2:08 PM, Peter Eisentraut wrote:
> > > On tis, 2010-11-16 at 14:00 -0800, Josh Berkus wrote:
> > >> It seems to me
> > >> that most people using unlogged tables won't want to back them up ...
> > >> especially since the share lock for pgdump will add overhead for the
> > >> kinds of high-volume updates people want to do with unlogged tables.
> > > 
> > > Or perhaps most people will want them backed up, because them being
> > > unlogged the backup is the only way to get them back in case of a
> > > crash?
> > 
> > Yeah, hard to tell, really.   Which default is less likely to become a
> > foot-gun?
> 
> Well. Maybe both possibilities are just propable(which I think is
> unlikely), but the different impact is pretty clear.
> 
> One way your backup runs too long and too much data changes, the other way
> round you loose the data which you assumed safely backuped.
> 
> Isn't that a *really* easy decision?
Oh, and another argument:
Which are you more likely to discover: a backup that runs consistenly running 
for a short time or a backup thats getting slower and larger...

Andres