[OSM-dev] osm2pgsql and bbox imports

[Peter Wendorff]

Hi Stephan.

osm2pgsql has to store nodes outside the bbox because geometries that 
overlap the borders etc. should be included in the result, too.
If osm2pgsql would skip nodes outside while parsing nodes, but before 
parsing the more complex geometries (ways, relations), these nodes would 
be lost later, even if they are necessary, e.g. for a big forest 
spanning the entire area etc.

Yes, preprocessing might be faster therefore, but that might depend on 
your system setup and where the bottleneck of your pipeline is, as the 
cutting process faces the same problem here: it runs several times over 
the input file to find dependent nodes for ways that are partly in the 
extracted target area.

regards
Peter

Am 12.10.2012 09:47, schrieb Stephan Knauss:
> Hi,
>
> I'm doing a slim mode bbox import for rendering.
>
> What is supposed to be in the planet_osm_nodes table? All nodes of my 
> import source file or only the nodes contained in the bbox?
>
> I used this bbox:
> --bbox  "97.3,5.6,109.6,23.4"
>
> and planet_osm_nodes contains for example this:
>
> id;lat;lon
> 1744503310;1003244360;-1936959139;
>
> Is it supposed to be there?
> If so, it would be a lot faster to preprocess the input file with bbox 
> clipping before feeding it into osm2pgsql.
>
> Was this changed recently? I have the impression that in the past it 
> did not contain these nodes.
>
> Stephan
>
> _______________________________________________
> dev mailing list
> dev at openstreetmap.org
> http://lists.openstreetmap.org/listinfo/dev
>