In retrospect this should actually (obviously) have been a question for the PostGIS list.
Please ignore the line about incorrectly reporting the GEOS version, that was user error I think! Cheers, James Sewell Developer LISAsoft Ph: +61 3 8680 3250 Fax: +61 3 8680 3299 Level 9, 601 Bourke St, Melbourne Vic 3000 LISAsoft is part of the A2end Group of Companies http://www.ardec.com.au http://www.lisasoft.com http://www.terrapages.com -----Original Message----- From: geos-devel-boun...@lists.osgeo.org [mailto:geos-devel-boun...@lists.osgeo.org] On Behalf Of james.sew...@lisasoft.com Sent: Friday, 18 February 2011 2:23 PM To: GEOS Development List Subject: [geos-devel] Nightly build performance Greetings GEOS Devs, I have been trying the GEOS and POSTGIS from a nightly build to test ST_Snap. I am still trying it out but have come across another issue. I am currently running the following: POSTGIS="2.0.0SVN" GEOS="3.3.0-CAPI-1.7.0" PROJ="Rel. 4.7.1, 23 September 2009" LIBXML="2.6.26" USE_STATS And comparing performance to: POSTGIS="1.5.2" GEOS="3.3.0-CAPI-1.7.0" PROJ="Rel. 4.7.1, 23 September 2009" LIBXML="2.6.26" USE_STATS (The first GEOS is actually nightly while the second isn't - yet they report the same version) The issue I have noticed is that the newer version is noticeably (more than 5x) slower on some large queries of the form: SELECT a.geom FROM left AS a, right AS b WHERE st_intersects(a.the_geom, b.the_geom); Have there been changes in this area of the code? Is this expected for nightly builds? Is there anything I can do to help troubleshooting of the issue? All my tables are imported and indexed by the same tool in both instances. Cheers, James Sewell Developer LISAsoft Ph: +61 3 8680 3250 Fax: +61 3 8680 3299 Level 9, 601 Bourke St, Melbourne Vic 3000 LISAsoft is part of the A2end Group of Companies http://www.ardec.com.au http://www.lisasoft.com http://www.terrapages.com -----Original Message----- From: geos-devel-boun...@lists.osgeo.org [mailto:geos-devel-boun...@lists.osgeo.org] On Behalf Of strk Sent: Thursday, 3 February 2011 7:14 PM To: GEOS Development List Cc: jts-topo-suite-u...@lists.sourceforge.net Subject: Re: [geos-devel] RE: [Jts-topo-suite-user] JTS Topology error On Thu, Feb 03, 2011 at 10:25:08AM +1030, james.sew...@lisasoft.com wrote: > (Crossposting to GEOS list) > > I see. So the difference between the GeometryNoder with a PrecisionModel and > using ST_Snaptogrid from PostGIS on the input geometries is that the > GeometryNoder snaps all nodes which are created by the noding process as it > works? > > This seems like an elegant solution to deal with the roundoff issues. > > I gather GEOS doesn't expose noding functionality in this way? Is this > something that could possibly be added? From PostGIS would a command like > ST_Node(geometry, 10E-10) make sense / be plausible? Or would a better > solution be to define the precision for each geometry column? Check the new ST_Snap() function in PostGIS and GEOS svn repository. --strk; () Free GIS & Flash consultant/developer /\ http://strk.keybit.net/services.html _______________________________________________ geos-devel mailing list geos-devel@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/geos-devel _______________________________________________ geos-devel mailing list geos-devel@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/geos-devel _______________________________________________ geos-devel mailing list geos-devel@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/geos-devel