John Smith wrote: > > > --- On Tue, 28/7/09, Shaun McDonald <sh...@shaunmcdonald.me.uk> > wrote: > >> Only use the is_in tag on the place nodes rather than every node. > > Why? > > The reasoning I've been given so far is for routing, but to find such > information routing software would have to look at all nodes near by > until it found the node tagged with the place information.
The reason I gave was for name searching, not routing. It allows the result of a search to be given a descriptive context that isn't currently possible any other way. This already works and it is a shame to break it because of dogma. Given a place (or any other object, but as Shaun said, places are the key things), determining for every place which county, state, country a place is in is complicated and will take a lot of compute resources. It amounts in principle to comparing each point against every boundary polygon in the world. Yes there are optimizations and short cuts, but it will nevertheless be a lot of work to do. And given that places don't move around significantly, we'll want to store the result in order to avoid recomputing it every time - and we have a natural place in which to store it already. We can give ourselves a helping hand here if we keep is_in. David _______________________________________________ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
