[postgis-users] ST_Union does not exist

[Dylan Beaudette]

Hi,

Noticed this today:

-- basic query
SELECT ST_Buffer(ST_UNION(wkb_geometry), 0.1) as wkb_geometry
FROM
	(
	SELECT 1 as id, wkb_geometry
	FROM map
	) as a 
GROUP BY a.id;

-- error message
ERROR:  function st_union(geometry) does not exist

-- software version (Postgresql 8.3.7)
POSTGIS="1.3.6" GEOS="3.0.0-CAPI-1.4.1" PROJ="Rel. 4.6.0, 21 Dec 2007" 
USE_STATS

Could this be related to my recent upgrade from postgis 1.3.3 ? Other postgis 
queries seem to work.

I was able to get a result using GeomUnion(geometry)--- but for anything more 
than a couple features this would take > 1 hour, not finishing, and could not 
be canceled by the user.

Grepping through the source reveals:
/src/postgresql-8.3.7/contrib/postgis-1.3.6$ grep -R -i 'st_union(geometry)' *

postgis_comments.sql:COMMENT ON AGGREGATE ST_Union(geometry) IS 'args: 
g1field - Returns a geometry that represents the point set union of the 
Geometries.';

Ideas?

Dylan


-- 
Dylan Beaudette
Soil Resource Laboratory
http://casoilresource.lawr.ucdavis.edu/
University of California at Davis
530.754.7341