Re: force the use of a particular index

On Fri, 2003-07-11 at 14:14, Rod Taylor wrote:
> > > set enable_hashjoin = false;
> >
> > BINGO!
>
> I'm not so sure about that. Your dataset seems to have changed fairly
> significantly since the last test.
>
> > -> Index Scan using feature_pkey on feature f (cost=0.00..134592.43 rows=47912 width=39) (actual time=0.46..502.50 rows=431 loops=1)
>
> Notice it only pulled out 431 rows where prior runs pulled out several
> thousand (~13000). I think what really happened was something came
> along and deleted a bunch of stuff, then vacuum ran.

There is nearly a zero chance that happened. This database is
accessible only by me, I haven't deleted anything. The only things I
have done is to create and drop various indexes and run vacuum. Is
there anything else that could explain the difference? Is the index
scan on feature_pkey using information from the index scan on
featureloc_src_6 to limit the number of rows to get from feature?

Scott

--
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Scott Cain, Ph. D. cain(at)cshl(dot)org
GMOD Coordinator (http://www.gmod.org/) 216-392-3087
Cold Spring Harbor Laboratory