[postgis-users] ST_MakeValid

[Stephen V. Mather]

Credit where credit is due-the cleanGeometry function listed below is
written by Horst Duester.

 

Best,

Steve

 

http://www.clemetparks.com/images/esig/cmp-ms-90x122.pngStephen Mather
Geographic Information Systems (GIS) Manager
(216) 635-3243

svm at clevelandmetroparks.com
 <http://www.clemetparks.com/> clevelandmetroparks.com

 

 

 

 

From: postgis-users-bounces at postgis.refractions.net
[mailto:postgis-users-bounces at postgis.refractions.net] On Behalf Of Stephen
V. Mather
Sent: Monday, April 16, 2012 12:33 PM
To: postgis-users at postgis.refractions.net
Subject: [postgis-users] ST_MakeValid

 

Hi All,

                Has anyone done any performance tests on ST_MakeValid?  I
had been using Tim Sutton's cleanGeometry function from circa 2010
(http://linfiniti.com/2010/07/cleaning-geometries-inside-postgis/) to clean
up geometries.  Works most of the time-every now and then I throw it
something too big and harry and it runs for weeks and weeks and never (AFAI
have the patience for) completes.  I've been looking forward to
ST_MakeValid.

                Today, a new Postgis 2.0 instance in hand, I was playing
with a dataset with 9106 invalid geometries-all self intersecting geometries
from raster-->vector conversion in an un-named proprietary package.  On a
whim, I decided to compare the speed of ST_MakeValid to Tim's code, so first
I needed the correct functions:

 

psql -U postgres -d test -f "C:\Program
Files\PostgreSQL\9.1\share\contrib\postgis-2.0\legacy.sql"

 

Then a quick run through cleanGeometry:

 

CREATE TABLE tpi_clean AS

     SELECT gid, id, gridcode, "class name", cleanGeometry(geom)

           FROM tpi;

 

And I get back:

 

Query returned successfully: 1004952 rows affected, 955444 ms execution
time.

 

If I run as ST_MakeValid,

 

CREATE TABLE tpi_valid AS

     SELECT gid, id, gridcode, "class name", ST_MakeValid(geom)

           FROM tpi;

 

At 2300000 milliseconds, it is still running. .

 

This is PostgreSQL 9.1, PostGIS 2.0 USE_GEOS=1 USE_PROJ=1 USE_STATS=1, on
Windows XP 32-bit.  I have not yet tested on my Ubuntu box. .

 

Thanks,
Best,

Steve

 

 

http://www.clemetparks.com/images/esig/cmp-ms-90x122.pngStephen Mather
Geographic Information Systems (GIS) Manager
(216) 635-3243

svm at clevelandmetroparks.com
 <http://www.clemetparks.com/> clevelandmetroparks.com

 

 

 

 

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