Even Rouault wrote: > Le samedi 21 avril 2012 12:41:49, Jukka Rahkonen a écrit : >> Hi, >> >> Martin Davis started this thread on OpenJUMP-dev list >> http://thread.gmane.org/gmane.comp.gis.jump.devel/11119 >> Perhaps someone would like to test how OGR performs with such data? >> Link to dataset is mentioned in the discussion.
> I suppose that dataset you mention is : > http://maps.cmparks.net/geoserver/metroparks/ows?service=WFS&version=1.0.0&request=GetFeature&;>typeName=metroparks:tpi_1&outputFormat=SHAPE- ZIP ? Exactly. > If so, on my box, the whole shapefile (~ 390 MB for the .shp / ~1 million > features) can be read in about 4 seconds with a simplified version of ogrinfo > that just loops on all the features. The algorithm that assembles the rings of > polygon shapes into polygons that conform to Simple Features has been pretty > improved during the last years. It is in the > OGRGeometryFactory::organizePolygons() method ( see > http://trac.osgeo.org/gdal/browser/trunk/gdal/ogr/ogrgeometryfactory.cpp#L1015 > ) . For shapefiles, there's a shortcut that save a lot of computations w.r.t. > the general algorithm, because the shapefile specification states that outer > rings should be described clockwise , whereas inner rings should be described > counter-clockwise. Thus it is 4 seconds vs. 32 seconds measured by Martin. It is a considerable difference but perhaps Martin is not doing exactly the same thing. Anyway, speed of OGR seems to be excellent. -Jukka Rahkonen-_______________________________________________ gdal-dev mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/gdal-dev
