[pgrouting-users] Re: Fwd: NiuRouting, PgRouting for SQLite

[Max Weninger]

Hi

On Thu, 23 Feb 2012 11:26:49 +0200
Jaak Laineste <jaak at nutiteq.com> wrote:

> 
> What is the project you're talking about here?

That is my "own" home-grown current project
of creating a car-navigation tool based on

-OSM 
-mapnik for map generation
-SQLite + spataialite for some geom data
-trsp algorithm from pgrouting

So my comment about the time needed to build
the graph is for trsp.

I have not done memory cosumption measurments
how much memory a trsp graph needs. In my "environment"
memory is not really a "hard limit". Time is more important.

Regards

max

> Spatialite Djikstra does not really have any query to fetch the data,
> where bbox could be applied. My understanding is that: a) in
> pgRouting with every calculation you query route data, graph is built
> based on it, and graph calculation is done. To reduce data in query
> you can use BBOX b) in Spatialite Djikstra you pre-generate graph for
> a table, so you have it as binary fields in special table. This is
> done once. From about 300MB of routes I got 20MB of graph data. For
> query this graph is loaded to RAM for calculations, and if you dont
> have enough of it then it crashes. Actually graph generation itself
> is quite fast, maybe it could be done for every query, then BBOX
> system could be hacked in reduce graph size. 
> 
> Anyway still bbox limit trick does not scale, especially for longer
> diagonal roads like "from Seatlle to Florida".
> 
> My question was what is approach of NiuRouting to pregenerate and
> keep graph data?
> 
> Jaak_______________________________________________
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