Re: help with getting index scan

On 25 Feb 2002, Doug McNaught wrote:

> "Thomas T. Thai" <tom(at)minnesota(dot)com> writes:
>
> > On 25 Feb 2002, Doug McNaught wrote:
> > > Well, EXPLAIN is indicating (unless I misread it) that the estimate of
> > > rows returned is 336702, so it's not surprising that it opts for a
> > > sequential scan. Is this under 7.1 or 7.2? The latter keeps much
> > > better statistics about table populations...
> >
> > this is under 7.2. is there away to force it to use index scan? cause
> > right now when i'm searching using a cat reference, it's taking a few
> > seconds.
>
> I'm still suspicious that something is wrong, but you can do
>
> SET enable_seqscan TO off;
>
> before your query and see if it helps your performance. If it makes a
> significant difference let us know--Tom may be interested in trying to
> improve the statistics.

i just tried turning off seq scan and the query still takes up to 8
seconds which is 7 seconds too long. btw, how do you clean the cache
from the last query?