AW: [postgis-users] Dissolve obsolete polygon borders

[Düster Horst]

strk

Thank you for your response. I doesn't work, PostgreSQL responses with 
"GEOS union() threw an error!".

Horst


-----Ursprüngliche Nachricht-----
Von: strk [mailto:strk at keybit.net]
Gesendet am: Mittwoch, 15. Oktober 2003 14:58
An: PostGIS Users Discussion
Betreff: Re: [postgis-users] Dissolve obsolete polygon borders

Try this:

CREATE AGGREGATE unite (
        sfunc = GeomUnion,
        basetype = geometry,
        stype = geometry
); -- this creates an aggregate out of GEOS's geomunion()

-- and this is your query 
SELECT your_attribute, unite(the_geom)
	FROM your_table
	GROUP BY your_attribute;

Note that GEOS cvs version is pretty memory absorbing (actually leaking)
and probably also buggy. Please let me know whether it worked for you.

--strk;

Horst.Duester wrote:
> Is there a way to dissolve obsolete borders between polygons with equal
> attributes??
>  
> I will appreciate your hints.
>  
> Horst
> 
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