[OSM-talk] Mapnik maxing CPU with Corine data set

Lennard ldp at xs4all.nl
Mon Jan 17 20:04:08 GMT 2011


On 17-1-2011 20:55, Frederik Ramm wrote:

> It will certainly be stored in the DB because osm2pgsql does not know
> about rendering rules. Plus, there it at least one query in the standard
> rendering rules that will actually *retrieve* such a polygon and return
> it to the Mapnik library for processing (where it will then be discarded):

It will not be discarded if it has a name=* ! :-)

Also, mapnik does a cheap bbox intersect to see which objects are likely 
to be in the tile to be rendered, instead of an expensive intersect. 
Depending on the size and position of your sea polygons, its bbox and 
the bbox of the tile being rendered could overlap even for tiles far inland.

-- 
Lennard



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