Re: Make COUNT(*) Faster?

On Fri, 2005-07-08 at 17:34 +0200, Dawid Kuroczko wrote:
> On 7/8/05, Rod Taylor <pg(at)rbt(dot)ca> wrote:
> > Create 2 sequences, one for counting tuple additions and one for
> > counting tuple deletions.
> >
> > When you INSERT a tuple, bump the "added" sequence (select nextval());
> >
> > When you DELETE a tuple, bump the "deleted" sequence (select nextval());
> >
> > To retrieve an approximate count, take the current value of both
> > sequences (select directly -- don't use currval) and subtract the
> > "deletes" from the "adds".
>
> Never thought of that! Good idea. :-)
>
> Regards,
> Dawid
>
> PS: There aren't any on ROLLBACK triggers, right? ;-)))

No. You could make then RI triggers and have them deferred until commit
though.

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