[OSM-dev] [Mapnik-users] How does Mapnik know which nodes are "important"?

[Gabriel Ebner]

On Thu, Dec 27, 2007 at 02:06:48AM +0000, Jon Burgess wrote:
> > By using QuadTiles, you only have to look at 120,000 nodes (10,000
> > nodes each for the QuadTile and all of its parents) to determine what to
> > map. Of course, you could use this in conjunction with spatial
> > indexing to make things even faster.
> 
> We do not directly deal with this level of detail in Mapnik. The
> PostgreSQL Postgis extensions deal with efficiently performing spatial
> queries on the data in the tables. It uses an radix-index scheme which
> I believe is a more generalised form of quad-tiling.

AFAIK postgis uses R-trees for indexing, i.e. no sort of tiling whatsoever.

  Gabriel.