[OSM-talk] Mapnik has busstops

[Schuyler Erle]

* On  3-May-2007 at  7:26AM PDT, Raphaël Jacquot said:
> Robert (Jamie) Munro a écrit :
> 
> > These spatial columns are not part of the logical model of the data,
> > which remains unchanged, they are just added as a sort of index or
> > cache. Mapnik should be able to work directly from these columns, and
> > you won't have to wait a week for Planet.osm, or even an hour for T at H to
> > see your changes, they will be rendered instantly once you have uploaded
> > them. As a side effect, the API will run a lot quicker because it will
> > be able to use the spatial columns to speed queries.
> 
> that's rather interesting...
> it sounds pretty similar to what I had done with postgres alone and
> geometry objects (and triggers to update things automagically)

That's basically what I'm doing now. I have some preliminary results
that show that *within PostgreSQL* spatial queries on the OSM database
are between 2.5x and 300x faster than their non-spatially-cached-
and-indexed counterparts, depending on whether you're asking for nodes
or ways within a bounding box. Naturally, I have no idea how this
compares to the current MySQL setup. Based on this very preliminary
finding, I'm going to proceed with my experiments in running the OSM
Rails server on PostGIS. If anyone else is interested in collaborating
on this, please let me know -- I'm not so good with Rails, I'm afraid.

SDE