Re: Make COUNT(*) Faster?

On Fri, 2005-07-08 at 17:34 +0200, Dawid Kuroczko wrote:
> On 7/8/05, Rod Taylor <pg@rbt.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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