On Oct 27, 2013, at 5:22 AM, Sandro Santilli wrote: > On Sat, Oct 26, 2013 at 06:27:41PM -0500, William Kyngesburye wrote: >> Is there any way to spatially index topogeometry? > > Nope, due to the fact that TopoGeometry spatial extent is not > in the value itself but derived using a volatile function from > external (referenced) data. > > This is a known problem: > http://trac.osgeo.org/postgis/ticket/2124 > http://trac.osgeo.org/postgis/ticket/853 > > One idea would be to make the && operator be > implemented by an SQL-defined function to be > fully inlined and thus giving the planner enough > hints to use the index on the underlying primitive > tables, but feasibility of that is uncertain. > > Another idea would be to introduce a trigger-based > mechanism to update some form of bbox cache into > each TopoGeometry affected by any change into any > primitive table, and then use that cache in select > querys. Note that making it transparent (using && > operator) would require a change in the TopoGeometry > structure, to add a bounding box field. > > --strk;
OK. So for now, working with a large topology data set is not practical. Some processing should not be a problem, if it operates on the primitives, which are indexed. ----- William Kyngesburye <kyngchaos*at*kyngchaos*dot*com> http://www.kyngchaos.com/ Earth: "Mostly harmless" - revised entry in the HitchHiker's Guide to the Galaxy _______________________________________________ postgis-users mailing list [email protected] http://lists.osgeo.org/cgi-bin/mailman/listinfo/postgis-users
