[postgis-users] what function to "dissolve" data?

[Andreas Laggner]

Hi,

i want to simplify my data by dissolving lines (borders) between 
Polygons (the polygons share one line or at least one point) with the 
same attributes to get a smaller dataset and i did not find a function 
for that operation (so far). For example i have one million polygons 
with the same landuse but a different polygon_number or what else and i 
only want to distinguish between landuse in my data. Thus i can reduce 
my dataset to same hundred polygons (or perhaps even one big polygon if 
all polygons touches).

thanks for help                  Andreas



-- 
Dipl. Geoökologe Andreas Laggner
Institut für Ländliche Räume (LR)
Bundesforschungsanstalt für Landwirtschaft (FAL)

Institute of Rural Studies
Federal Agricultural Research Centre (FAL)

Bundesallee 50
D-38116 Braunschweig

Tel.: (+49) (0)531 596 5515
Fax: (+49) (0)531 596 5599
E-mail: andreas.laggner at fal.de
Homepage: http://www.lr.fal.de/