[OSM-dev] Best way to select from a region
osm at stephans-server.de
Tue Sep 1 21:23:39 BST 2009
Roland Olbricht wrote:
that sounds cool. Did not know it before. It's not advertised a lot ;)
What are the limits? Frederik mentioned a query against a polygon might
be slow. Which area could be returned? Only a city? Bavaria? France?
I don't want to use xapi. The area can only be described by a bounding
box. I even feel the poly files available at cloudmade are too
inaccurate. In some places they are off by a huge distance.
And interesting places often tend to be near borders that mark boundaries.
Has someone already implemented a way to view those .poly files in
openlayers? Could help to determine which areas are affected.
I also thought about maybe using a rectangular box to update the data
and from time to time use the expensive polygon match to "blacklist"
nodes outside the polygon. Those could be subtracted from the box.
Assuming not much changes in those areas the number of false matches
might be low.
Or maybe only query the nodes near the border against the expensive polygon?
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