It's odd for union to return no result. The "high speed" union can only kick in when run against collections consisting entirely of polygons. If you have a non-polygon, you'll get the old behavior. You might even get the old behavior if you have a null in there, that's a case I'm not sure of.
P. On Fri, Aug 7, 2009 at 10:37 PM, Simon Greener<si...@spatialdbadvisor.com> wrote: > To those who asked for a test case. > > I prepared and sent a test case to Regina to ensure it was a good test set > before sending it on to the discussion list. > > Regina tested it and reported to me that: > > "I tested this against GEOS 3.2 SVN and it worked. Against GEOS 3.1.1 it > doesn't." > > I was running GEOS 3.1.1 as part of the standard PostGIS 1.4 on PostgreSQL > 8.4 combo. > > Regina provided me with the compiled GEOS 3.2 libraries: > > SELECT postgis_full_version(); > "POSTGIS="1.4.0" GEOS="3.2.0-CAPI-1.6.0" PROJ="Rel. 4.6.1, 21 August 2008" > USE_STATS" > > I can confirm that my data is now successfully processed by PostGIS's > ST_Union though it isn't all that fast: > > "Query returned successfully with no result in 5011922 ms." = 1hr 23min which > is pretty slow. > > Any idea why? > > regards > Simon > -- > SpatialDB Advice and Design, Solutions Architecture and Programming, > Oracle Database 10g Administrator Certified Associate; Oracle Database 10g > SQL Certified Professional > Oracle Spatial, SQL Server, PostGIS, MySQL, ArcSDE, Manifold GIS, FME, Radius > Topology and Studio Specialist. > 39 Cliff View Drive, Allens Rivulet, 7150, Tasmania, Australia. > Website: www.spatialdbadvisor.com > Email: si...@spatialdbadvisor.com > Voice: +61 362 396397 > Mobile: +61 418 396391 > Skype: sggreener > Longitude: 147.20515 (147° 12' 18" E) > Latitude: -43.01530 (43° 00' 55" S) > NAC:W80CK 7SWP3 > _______________________________________________ > postgis-users mailing list > postgis-users@postgis.refractions.net > http://postgis.refractions.net/mailman/listinfo/postgis-users > _______________________________________________ postgis-users mailing list postgis-users@postgis.refractions.net http://postgis.refractions.net/mailman/listinfo/postgis-users
