I have to create a big polygon with the outer ring from some selected polygons that are close to each other like in the picture.
Is it somehow possible two fill the small gap between the polygons as shown in the other picture
I'm using this query:
SELECT ST_ExteriorRing((ST_DUMP(ST_Union(the_geom))).geom) FROM parcel
to get the outer line but get 4 rows result.
What do I've to do to get only one row of the outer line without the gaps?