Forgot to reply all... > The ST_MakeValid tries its best to retain all input vertices.
AFAIK, Horst's function does as well. > Also, ST_MakeValid internally checks for input validity and avoids > running anything if the input is valid. Such check has a cost too. Horst's function naturally leverages the old "isValid". I'm going to try on one of the datasets that Horst's function fails on, as I suspect the new native function is less likely to fail. I'll take stability over speed (most of the time, anyway...). FYI, an excerpt from the code from Horst's function --------------------- http://www.sogis1.so.ch/sogis/dl/postgis/cleanGeometry.sql Does the following for the polygon case: IF (GeometryType(inGeom) = 'POLYGON' OR GeometryType(inGeom) = 'MULTIPOLYGON') THEN -- Only process if geometry is not valid, -- otherwise put out without change if not isValid(inGeom) THEN -- create nodes at all self-intersecting lines by union the polygon boundaries -- with the startingpoint of the boundary. tmpLinestring := st_union(st_multi(st_boundary(inGeom)),st_pointn(boundary(inGeom),1)); outGeom = buildarea(tmpLinestring); IF (GeometryType(inGeom) = 'MULTIPOLYGON') THEN RETURN st_multi(outGeom); ELSE RETURN outGeom; END IF; else RETURN inGeom; END IF; ... 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
