Re: Re: Performance degradation in PostgreSQL 7.1beta3 vs

"Robert E. Bruccoleri" wrote:
>
> Dear Hannu,
> >
> > "Robert E. Bruccoleri" wrote:
> > >
> > > explain select count(*) from comparisons_4 where code = 80003;
> > > NOTICE: QUERY PLAN:
> > >
> > > Aggregate (cost=15659.29..15659.29 rows=1 width=0)
> > > -> Seq Scan on comparisons_4 (cost=0.00..15640.81 rows=7391 width=0)
> > >
> > > EXPLAIN
> >
> > What is the type of field "code" ?
>
> int4
>
> Do you think that should make a difference?

Probably not here.

Sometimes it has made difference if the system does not recognize
the other side of comparison (80003) as being of the same type as
the index.

what are the cost estimates when you run explain with seqscan disabled ?
do => SET ENABLE_SEQSCAN TO OFF;
see:
(http://www.postgresql.org/devel-corner/docs/admin/runtime-config.htm#RUNTIME-CONFIG-OPTIMIZER)
-----------------
Hannu