Re: Postgresql backend to perform vacuum automatically

Bruce Momjian wrote:
>
> Neil Padgett wrote:
> > On Tue, 2002-03-05 at 15:59, Bruce Momjian wrote:
> > > > > > If they do not affect performance, then why have them off?
> > > > >
> > > > > I think Jan said 2-3%. If we can get autovacuum from it, it would be a
> > > > > win to keep it on all the time, perhaps.
> > > >
> > > > Assuming that the statistics get updated:
> > > >
> > > > How often should the sats table be queried?
> > > > What sort of configurability would be needed?
> > >
> > > You could wake up every few minutes and see how the values have changed.
> > > I don't remember if there is a way to clear that stats so you can see
> > > just the changes in the past five minutes. Vacuum the table that had
> > > activity.
> >
> > Ick -- polling. The statistics process should be able to wake somebody
> > up / notify the postmaster when the statistics change such that a vacuum
> > is required.
>
> Yes, that would tie that stats collector closer to auto-vacuum, but it
> certainly could be done.

Using an alert can be done, but polling is easier for a proof of concept. I
dont see too much difficulty there. We could use notify.