[postgis-users] performace question

[Martin Landa]

Hi,

I am beginning with PostGIS and I wonder about performance, e.g.
having layer 'regions' = 'obce' (polygon) and boundary of CZ = 'cr'
(polygon).

SELECT count(obce.gid) FROM obce;
 count
-------
  6361
(1 row)

SELECT count(obce.gid) FROM obce,cr WHERE ST_Touches(obce.the_geom,
cr.the_geom);
 count
-------
   285
(1 row)

Time: 258271.730 ms

It seems to be quite long time, any hits about configuration of
PostgreSQL, query optimalization?

PostgreSQL 8.1.15,  1.4 USE_GEOS=1 USE_PROJ=1 USE_STATS=1

Thanks in advance, Martin

-- 
Martin Landa <landa.martin gmail.com> * http://gama.fsv.cvut.cz/~landa