[OSM-dev] Best way to select from a region
osm at stephans-server.de
Tue Sep 1 00:56:20 BST 2009
I'm trying to create lists of features inside a specific country.
What would be the most convenient way to do this?
As source I could either use a planet file and use a SAX parser or
PostgreSQL with the osm2pgsql mapnik schema.
As a boundary polygon I would prefer the borders already in the database
as these are more accurate compared to the polygon files of cloudmade.
I saw the table planet_osm_line contains the boundary relations. Could
that be used?
planet_osm_point contains the tags already decoded into columns. But i
would need to join this to do the restriction to the bounding-polygon,
right? Would it be better to use planet_osm_nodes, select the tags and
later throw away false positive matches? For example to match an amenity
is easy using the _point table. With the _nodes table I might match a
different key containing the same value.
Is there already an index to speed up the spatial query of should I
better create one?
For the SAX approach I would need to build a spatial index, right? I
never worked with geometry data types before, so I have a lot of things
to learn. Sure an interesting topic...
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