[postgis-users] Another Question on PostGIS Performance

[Thomas Haechler]

Hello,

I'm quite new to PostGIS. In my mapserver application, I have added a
postgis polygon layer for testing. Since then, it takes about 15 secs to
render the map on a Sun Ultra 60/300. This seems rather long and I would
appreciate any help on how to make this faster.

Some "test" results:

1.) standard map with 1 raster & 1 line layer (shapefile) : 2 secs

2.) dito + the addidtional polygon layer from shapefile : 7 secs

3.) dito + DATA "the_geom from veg": 13 secs

4.) dito + DATA "the_geom from ( select map.the_geom, data.hs_zoller,
map.gid from veg as map, veg_atr as data where map.pg = data.pg )as foo
using unique gid": 15 secs

5.) only postgis layer DATA "the_geom from ( select map.the_geom,
data.hs_zoller, map.gid from veg as map, veg_atr as data where map.pg =
data.pg )as foo using unique gid": 15 secs

Is it normal for this layer alone to take about double the time to
render with postgis than from shapefile?
Yes, I have a gist index on the_geom and an oid index on the map.gid and
data.pg columns, and I did vacuum analyze.


Thank you in advance,



-- 

THOMAS HAECHLER

Geographic Information Systems Division
Institute of Geography
University of Zurich
Switzerland

thomas.haechler at geo.unizh.ch