Thanks for the quick answer. Just read your writeup on the subject [1]. This looks like a _very nice_ addition and should be extremely helpful. I've got some experimenting to do!
-=- Jerry [1] http://strk.keybit.net/projects/postgis/Paris2011_TopologyWithPostGIS_2_0.pdf In otherwords, you skip On Apr 11, 2012, at 11:51 AM, Sandro Santilli wrote: > On Wed, Apr 11, 2012 at 11:47:02AM -0400, Jerry Carter wrote: > >> I might have a geometry for a country and separate geometries for the >> next layer of administrative regions (e.g. states in the United States). >> But there are often minor differences in the polygons such that the >> polygon for the country is nearly but not exactly the union of the states. >> How is this handled? > > In the topology model your higher layer will be defined by composition > of lower layer items. So you would only say that "United States" is > formed by all the countries. And for each country you would only list > the counties they are formed of. And for each county the parcels. > And for each parcel the primitive faces. And each face is defined by > its edges. > > The only actual geometries involved in all of the above would be > the edge geometries. Not any other geometry. So there's no difference > because primitive elements are singletons. > > --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 _______________________________________________ postgis-users mailing list postgis-users@postgis.refractions.net http://postgis.refractions.net/mailman/listinfo/postgis-users
