[OSM-dev] Memory error while converting osm to gml

Stefan de Konink stefan at konink.de
Thu Apr 2 22:31:16 BST 2009

Matt Amos wrote:
> 2009/4/2 Stefan de Konink <stefan at konink.de>:
>> Iván Sánchez Ortega wrote:
>>> El Jueves, 2 de Abril de 2009, Will Nordin escribió:
>>>> I am trying to convert the planet-090319.osm (approx 107GB) to gml. I've
>>>> tried the Java and Python solutions, but both end up thorwing OutOfMemory
>>>> exceptions.
>>> Man, it's one-frakking-hundred gigabytes, how would it *not* cause OOM
>>> errors?!
>> We call it memory mapping or a streaming operation :) Especially with
>> sax like events perfectly doable :)
> except that GML describes linestrings. so you'd need to either store
> all the node locations in ram or some external indexed format... which
> is exactly what osm2pgsql does :-)

mmap the node table in array index form to disk, that will work because 
of hole allocation, that will result in a temporary file of around 5GB 
allocated space, now for any way you encounter you can do { node[2*nd] 
node[2*nd + 1] }. And get the line string upon any nd event.

> i second frederik's recommendation - import into postgres using
> osm2pgsql then export the GML from that. its a little convoluted, but
> the toolchain is well tested.

Does anyone have any timings on importing the current planet.osm in 
PostgreSQL with any tool available? Using lets say 8GB of ram and 
'typical' disk?


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