[postgis-devel] [PostGIS] #2024: ST_Union is buggy

PostGIS trac at osgeo.org
Mon Oct 1 17:34:21 PDT 2012

#2024: ST_Union is buggy
 Reporter:  robe     |       Owner:  pracine      
     Type:  defect   |      Status:  new          
 Priority:  blocker  |   Milestone:  PostGIS 2.1.0
Component:  raster   |     Version:  trunk        
 Keywords:           |  
 I think there is something wrong with the new implementation of ST_Union.
 I did a sample test on both my 2.0.1 and latest 2.1.0 and the 2.1.0 seems
 to be leaving out tiles.

 SELECT ST_AddBand(NULL,ARRAY[ST_Union(rast,1), ST_Union(rast,2),
 ST_Union(rast,3) ]), count(*)
 FROM test_100_100
 WHERE ST_Intersects(rast,  ST_GeomFromText('LINESTRING(230486.436 886271,
 230486.437 887771)',26986) );

 42 tiles should be glued.

 See attached files:

 The image I was testing with you can download from:


 And I ran this load to load it in:

 raster2pgsql -s 26986 -t 100x100 -F -t 100x100 -I -Y 23128870.jpg
 test_100_100 | psql -U postgres -d testpostgis21 -h localhost -p 5442

 I though it might be the ST_AddBand, but if I do just a union of a single
 band, I get the same issue.

Ticket URL: <http://trac.osgeo.org/postgis/ticket/2024>
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