[pgrouting-users] Optimize routing - use new sew-devel-2_0 functions

[Daniel Kastl]

On Wed, May 22, 2013 at 6:42 PM, Frédéric Bonifas <fredericbonifas at gmail.com
> wrote:

> I agree the the routes will be relatively short for pedestrian routing,
> but :
> * if I understand correctly how Dijkstra works, the routing time will
> mostly depend on the size of the graph, as the whole graph will be
> visited before giving the shortest_route.
> * the fastest it is, the more I like it :)
> * I show to the user different possible routes (4) so the routing time
> is multiplied by this factor.
>
>
Hi Frederic,

The algorithm doesn't make such  big difference as you might expect.
What matters is the size of the network that you load for a routing
request, which depends on the length of the route and the road density.
For example a 40km route through Tokyo will load a huge amount of data, but
some sparse area in Canada 40km would not be an issue.

For your pedestrian routing, did you make sure that you don't load the
whole network table for every request?
The easiest way to limit the data you select is using a BBOX.

 Daniel



-- 
Georepublic UG & Georepublic Japan
eMail: daniel.kastl at georepublic.de
Web: http://georepublic.de
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