[postgis-users] performace question

[Ivan Mincik]

On Wednesday 01 April 2009, Martin Landa wrote:
> 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?
Have You tried to make VACUUM on that table ?
> 
> PostgreSQL 8.1.15,  1.4 USE_GEOS=1 USE_PROJ=1 USE_STATS=1
> 
> Thanks in advance, Martin
>