[GRASS-dev] large vector and indices, speed up db

Moritz Lennert mlennert at club.worldonline.be
Fri Feb 27 08:36:46 EST 2009


On 27/02/09 14:19, Markus Metz wrote:
> 
> Moritz Lennert wrote:
>> Yes, querying the geometries is very slow currently because of the 
>> fact that the spatial and topological index is kept in memory and not 
>> on file, so every time you launch an interactive query, it has to 
>> rebuild it which is very slow on large vectors. See
>>
>> http://josef.fsv.cvut.cz/WIKI/grass-osgeo/index.php/GRASS_7_ideas_collection#Radim.27s_TODO_list 
>>
>>
> Does someone remember the reason why the spatial index is not (no 
> longer?) written to a file? Once the spatial index is (again?) written 
> to a file, all that rebuilding could be avoided by reading from the 
> file, that alone could give a speed increase.

http://www.intevation.de/rt/webrt?serial_num=3193

See also hints from Radim on how to implement file-based index:
http://lists.osgeo.org/pipermail/grass-dev/2006-September/025780.html

Moritz



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