Re: count(*) performance improvement ideas

On Wed, Mar 12, 2008 at 9:14 PM, Mark Mielke <mark(at)mark(dot)mielke(dot)cc> wrote:
>
> If you are talking about automatically doing this for every table - I
> have an objection that the performance impact seems unwarranted against
> the gain. We are still talking about every insert or update updating
> some counter table, with the only mitigating factor being that the
> trigger would be coded deeper into PostgreSQL theoretically making it
> cheaper?
>

No, I am not suggesting that. If you read proposal carefully, its one UPDATE
per transaction. With HOT, I am hoping that the counter table may be
completely cached in memory and won't bloat much.

Also, we can always have a GUC (like pgstats) to control the overhead.

Thanks,
Pavan

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