On Fri, May 25, 2012 at 08:21:25PM +1000, Luca Morandini wrote: > On 05/25/2012 07:26 PM, Sandro Santilli wrote: > >On Fri, May 25, 2012 at 01:52:45PM +1000, Luca Morandini wrote: > > > >>after seeing some polygons disappear during the generalization > >>process, I found out that ST_Union and ST_Collect are different > >>beasts when dealing with intersecting lines. > > > >Yes, ST_Collect simply puts things togheter. ST_Union computes the > >point set union. Isn't the manual page clear about that ? > > That is clear, what I did not suspect was the different behaviour > when there are "loops" in the collection of lines given as > argument... well, it may be ST_BuildArea that has a different > behaviour when the argument is a collection of linestrings or a > single geometry.
BuildArea is not an aggregate so won't "internally" collect the inputs. I'm not sure this solves your problem. --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
