[postgis-users] Dissolve obsolete polygon borders

[strk]

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

Try downloading the latest postgis from CVS repository, it now contains
new code to show a more meaningful message (thanks Dave).

--strk;

> 
> 
> -----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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> > postgis-users at postgis.refractions.net
> > http://postgis.refractions.net/mailman/listinfo/postgis-users
> 
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