[postgis-users] Is there a faster way to create a polygon overlay?

[Jeff Adams]

This is what I have:

INSERT INTO test_pieces
SELECT geom FROM St_Dump(
	(SELECT St_Polygonize(the_geom) AS the_geom
	 FROM
		(SELECT ST_Union(the_geom) AS the_geom
		 FROM
			(SELECT ST_ExteriorRing(polygon_col) AS the_geom
			 FROM myTable) AS lines
		 ) AS noded_lines
	 )
	)

My polygons are ugly though, there are about 5000 of them in myTable
but they overlap a lot (any given one overlaps 100+ others) so there
are going to be a lot of pieces.