Re: Same query doing slow then quick - Mailing list pgsql-performance

From Undertaker Rude
Subject Re: Same query doing slow then quick
Date
Msg-id SNT111-W4B0E4DDE4E182748D6813E1880@phx.gbl
Whole thread Raw
In response to Re: Same query doing slow then quick  (FFW_Rude <FFW_Rude@hotmail.com>)
List pgsql-performance
Oh, thankx. I forgot to put the answer i got from another site. I was told to use box and point type and create an index on it and it works really well !

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> Date: Sun, 7 Oct 2012 17:27:02 +0300
> Subject: Re: [PERFORM] Same query doing slow then quick
> From: ants@cybertec.at
> To: ffw_rude@hotmail.com
> CC: lystor@gmail.com; pgsql-performance@postgresql.org
>
> Sorry for the late answer, I was going through my e-mail backlog and
> noticed that this question hadn't been answered.
>
> On Thu, Sep 27, 2012 at 11:33 AM, Undertaker Rude <ffw_rude@hotmail.com> wrote:
> > Oh ok. But what is this command doing ? i'm gonna runn it today. I'll keep
> > you posted. Here is some EXPLAIN ANALYZE from the querys :
> >
> >
> > Nested Loop (cost=0.00..353722.89 rows=124893 width=16) (actual
> > time=261158.061..10304193.501 rows=99 loops=1)
> > Join Filter: ((t2."X" >= (t1.x_min)::double precision) AND (t2."X" <=
> > (t1.x_max)::double precision) AND (t2."Y" >= (t1.y_min)::double precision)
> > AND (t2."Y" <= (t1.y_max)::double precision))
> > -> Seq Scan on gps_22 t1 (cost=0.00..3431.80 rows=177480 width=44)
> > (actual time=0.036..1399.621 rows=177480 loops=1)
> > -> Materialize (cost=0.00..20572.83 rows=57 width=20) (actual
> > time=0.012..10.274 rows=2924 loops=177480)
> > -> Seq Scan on adresses_22 t2 (cost=0.00..20572.55 rows=57
> > width=20) (actual time=1570.240..1726.376 rows=2924 loops=1)
> > Filter: ((id_maille_200m)::text = '0'::text)
> > Total runtime: 10304211.648 ms
>
> As you can see from the explain plan, postgresql is not using any
> indexes here. The reason is the type mismatch between the X and x_min
> columns. Use matching types between tables to enable index use. The
> same goes for the id column, if the column type is integer use a
> numeric literal 0 not a text literal '0'.
>
> Regards,
> Ants Aasma
> --
> Cybertec Schönig & Schönig GmbH
> Gröhrmühlgasse 26
> A-2700 Wiener Neustadt
> Web: http://www.postgresql-support.de

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