[pgrouting-users] pgRouting Memory Issues

[Richard Marsden]

Daniel,

Thanks for your quick reply. Yes that was what I was trying to do with my
'WHERE' clause - I thought I was limiting the data pgRouting was looking at.

Going back to your earlier reply (about creating a VIEW for osm2po-produced
data), and combining with the info on the URL you provided below, I've
actually got a result back! I need to study things more, check what I'm
getting back, and work out how to get what I actually want; but I'm
definitely on the right track. Runtime was 1655ms which is also acceptable.
Although the bounding box was small, 1-2 secs/route is my target. However,
there's some leeway and it looks like app-level multi-threading will be
practical, but "minutes/route" would not be practical:  I have a lot of
routes to calculate!

Thanks,

Richard (M)




On Thu, Jan 13, 2011 at 10:05 PM, Daniel Kastl <daniel at georepublic.de>wrote:

> Hi Richard,
>
> When you make a query you select your whole network table into memory ...
> which is huge, if it's all planet.osm road data.
> To make this faster you should make a query, that only selects the road
> data you need. Why should you for example load North American roads, when
> you route in Europe.
>
> As smaller the amount of selected data is, as faster you will get the
> result. That's the trick ;-) And if you route long distances you might want
> to consider to create a layered network and run multiple queries.
> Look at the part with the bounding box wrapper. It applies for all
> algorithms, just look at Dijkstra chapter in the workshop:
> http://workshop.pgrouting.org/chapters/shortest_path.html#dijkstra
>
> Daniel
>
>
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