[Routing] How big is your graph? How long to find 30km route in your graph?

[Marcus Wolschon]

On Wed, 15 Oct 2008 03:38:45 -0700 (PDT), j2megps <j2megps at yahoo.com>
wrote:
> @Marcus
> So you are using database to model a graph, can you show me the graph's
> table structure in your database?

I am currently reworking it but it should stay fairly close
to a simple ways, nodes, node_of_way, attrib_of_way, attrib_of_node.
I used to use xml-files in the osm-schema split by tiles
because they where very easy to use inspect using josm and much
faster then I thought (outperforming mysql and hsqldb without 2d-indices
or with only a z-order-index). Now it's going to become mysql-gis.

> You are limiting to all of Baden-Württemberg (Germany), can you give the
> number of vertices and edges (i.e number of records in vertices table and
> edges table)?

No because the router loads updates and missing areas from the OSM-
server while routing. Thus it constantly changes.
This is also the reason I am not preprocessing the OSM-data.

why?
I want to preserve the ways and nodes to update them and to
allow the user to click the [edit in josm]-button to correct errors
in the currently visible area.
It also allows for very advances metrices, map-renderers and
experimental routing-algorithms.
Data-storage, routing, metrices, renderers, location-providers,
driving-instruction-generators, address-finders and
driving-instruction-output
are all plugins with multiple implementations to choose from
in Traveling Salesman. This router is for developers to have a
testbed to do their papers on routing-algorithms and metrices in.

> You did not load the whole graph into memory --> you are using sql
> statement
> to query against database each time your routing algorithmn vist a node?

No, I am using a memory-sensitive cache that uses as much memory as
is currently unused to cache reat or unwritten data.

> My routing application run on a system that has no database and only
1024KB
> (1MB) memory, so I have no choice but have to store all graph data in
flat
> files.

That sounds strange. What is the purpose of the device?
Is it for pedestriand, weelchairs, bikes?