Re: count(*) performance improvement ideas

On Wed, Mar 12, 2008 at 9:01 PM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
> "Pavan Deolasee" <pavan(dot)deolasee(at)gmail(dot)com> writes:
> > I am sure this must have been discussed before.
>
> Indeed. Apparently you didn't find the threads in which the idea of
> having transactions enter "delta" entries was discussed? Solves both
> the locking and the MVCC problems, at the cost that you need to make
> cleanup passes over the counter table fairly often.
>

Ok. I would surely look at those threads. Hopefully HOT will considerably
solve the counter table cleanup issue.

> I don't see this as material for the core DB but it would make a great
> contrib module.
>

I guess we will need some backend hooks to make it really work, no ?
At the minimum we need to track the "deltas" at the transaction level
and the ability to do some extra processing at the commit time.
May be I should first read those threads and I will find the answers.

Thanks,
Pavan

--
Pavan Deolasee
EnterpriseDB http://www.enterprisedb.com