Re: Vacuum only with 20% old tuples

On Wed, 12 Jul 2000, Bruce Momjian wrote:

> > 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) ...
>
> Would be good if we could to vacuum without locking. We could find a
> table when things are mostly idle, and it then.

Definitely :)