[OSM-talk] OSM maps on Garmin GPS

[raphael Jacquot]

Lars Aronsson wrote:
> Mikel Maron wrote:
>> I can see some tie ins with the new tiling infrastructure. For 
>> mapnik, queries are run against a PostGIS database (populated 
>> from planet.osm) which is part of the reason why it's so fast.
> 
> You make it sound like magic.  What is the essential algorithm or 
> data structure in PostGIS that causes this speed-up?  Could the 
> same speed be achived with the GIS extensions to MySQL?  Could it 
> be achieved by changing the old OSM tile generation code on top of 
> the regular MySQL?
> 
> 
simple...
the r-tree based GIST index on bounding boxes that's applied on the 
geometry column :D