Sorry for the confusion, the plans from morning and evening are really
different for sure.
Let me ensure with my team that postgresql configuration is not changed
between morning and evening and will recollect the data tomorrow.
On Wed, Feb 13, 2013 at 8:34 PM, Kevin Grittner <kgrittn@ymail.com> wrote:
> Carlos Henrique Reimer <carlos.reimer@opendb.com.br> wrote:
>
> > Anyway it does not seam related to statistics as the query plan
> > is exactly the same for both scenarios, morning and evening:
>
> > Morning:
>
> > Index Scan using pagpk_aux_mes, pagpk_aux_mes, pk_cadpag,
> > pk_cadpag, pk_cadpag, pagchavefunc00 on cadpag
>
> > Evening:
>
> > Seq Scan on cadpag
>
> Those don't look exactly the same to me.
>
> > I've used this query just as an example but the general feeling
> > is that everything takes more time to process in the evening.
> > Evening is also the period with more tasks in the the database.
>
> Well, if the resources are split among more processes, each process
> will take longer to run. No surprise there. Of course, there
> could be some interaction -- queries which do more work because
> statistics are out of date could contribute to the slowdown of
> everything else.
>
> --
> Kevin Grittner
> EnterpriseDB: http://www.enterprisedb.com
> The Enterprise PostgreSQL Company
>
--
Reimer
47-3347-1724 47-9183-0547 msn: carlos.reimer@opendb.com.br