Re: Improving count(*)

Simon,
Nice suggestion, I think it's workable but (like all other methods) has
some technical/pseudo-political challenges.
I'm still voting for my old, "Much Ado About COUNT(*)" topic; adding
visibiility to the indexes and counting them like the other RDBMS vendors.
True, it would add storage overhead that several people don't want, but such
as the life of the COUNT(*) discussion for PostgreSQL...
-Jonah

On 11/17/05, Martijn van Oosterhout <kleptog(at)svana(dot)org> wrote:
>
> On Thu, Nov 17, 2005 at 07:28:10PM +0000, Simon Riggs wrote:
> > One of the major complaints is always "Select count(*) is slow".
> >
> > I have a somewhat broadbrush idea as to how we might do this (for larger
> > tables).
>
> It's an interesting idea, but you still run into the issue of
> visibility. If two people start a transaction, one of them inserts a
> row and then both run a select count(*), they should get different
> answers. I just don't see a way that your suggestion could possibly
> lead to that result...
>
> There is no unique answer to count(*), it all depends on who is looking
> (sounds like relativity :) ). If you can sort that, you're well over
> 90% of the way.
>
> Have a nice day,
> --
> Martijn van Oosterhout <kleptog(at)svana(dot)org> http://svana.org/kleptog/
> > Patent. n. Genius is 5% inspiration and 95% perspiration. A patent is a
> > tool for doing 5% of the work and then sitting around waiting for
> someone
> > else to do the other 95% so you can sue them.
>
>
>