> IIRC there's a difference with a multipolygon composed by two > overlapping rectangles.
Rereading, does ST_MakeValid also test for overlapping polygons? This would explain the performance difference, as these polygons are pretty complicated, and checking for overlap would not be well served by bounding box indices. Best, Steve Stephen Mather Geographic Information Systems (GIS) Manager (216) 635-3243 s...@clevelandmetroparks.com clevelandmetroparks.com -----Original Message----- From: Sandro Santilli [mailto:sandro.santi...@gmail.com] On Behalf Of Sandro Santilli Sent: Monday, April 16, 2012 12:41 PM To: s...@clevelandmetroparks.com; PostGIS Users Discussion Subject: Re: [postgis-users] ST_MakeValid On Mon, Apr 16, 2012 at 12:33:15PM -0400, Stephen V. Mather wrote: > Then a quick run through cleanGeometry: ... > Query returned successfully: 1004952 rows affected, 955444 ms execution time. > > If I run as ST_MakeValid, ... > At 2300000 milliseconds, it is still running. . The ST_MakeValid tries its best to retain all input vertices. IIRC there's a difference with a multipolygon composed by two overlapping rectangles. Also, ST_MakeValid internally checks for input validity and avoids running anything if the input is valid. Such check has a cost too. --strk; ,------o-. | __/ | Delivering high quality PostGIS 2.0 ! | / 2.0 | http://strk.keybit.net - http://vizzuality.com `-o------' _______________________________________________ postgis-users mailing list postgis-users@postgis.refractions.net http://postgis.refractions.net/mailman/listinfo/postgis-users
