On Wed, Mar 19, 2014 at 06:43:21PM +0100, Rémi Cura wrote: > Hey, > > We tried several way to load an already topologically correct shapefile > into postgis topology . > > 10k lines loaded > _Using totopogeom : 750 sec > _Using addlinestring : 246 sec > _Manually using addnode and st_addedgemodface : 86 sec. > > Still very slow :-/ > > Considering manually filling table /and/or using GEOS/or using grass loader.
Interesting numbers, thanks. By "addlinestring" you mean TopoGeo_addLinestring ? Is this with postgis trunk ? Note that ST_AddEdgeModFace (called by TopoGeo_addLinestring) still performs checks to verify the line you add does not cross othe redges. There's currently no API exposed for simply adding the linking attributes (face left/right and next edges). I was thinking that one idea could be to manually insert all the nodes and edges and then have a function to "polygonize" the supposedly pre-noded resultance set. This would be pretty much the same model used by GEOSPolygonize (requires pre-noded input) and would probably be faster for batch constructions. To complete the picture, how long does it take to simply insert all your lines as edges ? So we get a feeling of IO and referential integrity checks cost... --strk; _______________________________________________ postgis-users mailing list [email protected] http://lists.osgeo.org/cgi-bin/mailman/listinfo/postgis-users
