Re: Vacuum only with 20% old tuples

On Wed, 12 Jul 2000, Bruce Momjian wrote:

> > > I do not see what your 20% idea has to do with this, though, nor
> > > why it's a good idea.  If I've told the thing to vacuum I think
> > > it should vacuum.  20% of a big table could be a lot of megabytes,
> > > and I don't want some arbitrary decision in the code about whether
> > > I can reclaim that space or not.
> > 
> > I wouldn't mind seeing some automagic vacuum happen *if* >20% expired
> > ... but don't understand the limit when I tell it to vacuum either ...
> 
> I am confused by your comment.

Make the backend reasonably intelligent ... periodically do a scan, as
you've suggested would be required for your above 20% idea, and if >20%
are expired records, auto-start a vacuum (settable, of course) ...