Message-ID: <3A4DD07C.73C236B7@tm.ee>
Date: Sat, 30 Dec 2000 14:09:32 +0200
From: Hannu Krosing <hannu@tm.ee>
MIME-Version: 1.0
To: Gilles Bernard <gbernard@matra-ms2i.fr>
CC: pgsql-docs@postgresql.org
Subject: Re: Postgres ignoring RTree for geometric operators
References: <200012290946.KAA01221@fwm1.matra-ms2i.fr>
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit

> Gilles Bernard wrote:
> 
> Hello, I'm trying to figure out how Postgres (7.0.3 on a DEC alpha
> OSF1 4.0F) deals with geometric types and operators.
> So I've create a table like this :
> 
> >create table geo
> >(
> >  id    int4 primary key,
> >  forme box,
> >  hmin  float4,
> >  hmax  float4,
> >  nom   varchar(40)
> >);
> 
> I've created a RTree index on the 'forme' field :
> 
> >create index geo_is on geo using RTREE (forme);
> 
> 
> The table is populated with 400,000 lines inserted like this :
> 
> >insert into geo values (1,
> '((51387.07,17572.56),(51440.62,17626.11))',30863.37,30916.92,'Donnee
> 1');
> >insert into geo values (2,
> '((94763.02,17172.77),(94785.77,17195.51))',70223.09,70245.83,'Donnee
> 2');
> >insert into geo values (3,
> '((49476.61,12469.86),(49515.67,12508.93))',8389.54,8428.60,'Donnee
> 3');
> > ...
> >insert into geo values (399998,
> '((86788.54,86867.89),(86857.69,86937.04))',86144.60,86213.75,'Donnee
> 399998');
> >insert into geo values (399999,
> '((94317.45,3723.26),(94413.56,3819.36))',70345.16,70441.27,'Donnee
> 399999');

Here you should probably do "vacuum analyze";

or just create the index _after_ inserting some amount of data tho have 
the initial statistics favour index scan


------------
Hannu