Yes there is slow down but I am not ready with the numbers yet and we have not focused to much on that now, because to go from simple feature to topology is a one time job in our case.
Whats more important is the update time when we apply changes to a exiting layer after it's created and that also involves adding new lines so we have to look more into this later, but an update in our case also involves line attribute handling and surfaces and surface attributes. I will have more numbers ready in July. Lars ________________________________________ Fra: [email protected] [[email protected]] på vegne av Marc-André Goderre [[email protected]] Sendt: 4. juni 2015 17:21 Til: PostGIS Users Discussion Emne: Re: [postgis-users] creating topology data is slow Does the processing became slower when the edge_data table became bigger? Marc -----Message d'origine----- De : [email protected] [mailto:[email protected]] De la part de Lars Aksel Opsahl Envoyé : 3 juin 2015 01:56 À : PostGIS Users Discussion Objet : Re: [postgis-users] creating topology data is slow We are working quite big datasets (about 1 billion points and 20 million lines) that we convert from simple feature to topology. I ran a test yesterday and we added these 20 million lines in about 9 hours with attached attributes. This means heavy parallel pressing and grid usage on a fast database, but we use the Postgis topology package mostly as it is (picked from trunk about a moth ago) . We will give a talk about how we do this at foss4g 2015 in Como in July. Lars ________________________________ Fra: [email protected] [[email protected]] på vegne av Rémi Cura [[email protected]] Sendt: 2. juni 2015 21:33 Til: PostGIS Users Discussion Emne: Re: [postgis-users] creating topology data is slow I'm working on a batch way to import topology, it is not ready yet. If you now for sure your data is correct, you can skip a lot of testing and be efficient in a batch way. You could use grass and the topological export. Cheers, Rémi-C 2015-06-02 19:25 GMT+02:00 Marc-André Goderre <[email protected]<mailto:[email protected]>>: Hello all, I'm creating topology data from almost all world road OSM data ( More than 77 Million ways). Processing the data with postgis topology in one shot is so long than that I created a hexagonal grid that let me create topological data from only one or many cell of the grid. Even this way, It' s going to take many month to process the world's data. Is there a way to make it faster? This is my function that I use to process data. CREATE OR REPLACE FUNCTION cm_update_tile_data(tile_id integer) RETURNS character varying AS $BODY$ DECLARE r RECORD; BEGIN FOR r IN SELECT * FROM way, join world_grid on line&& the_geom where gid=tile_id and topo_geom is NULL LOOP BEGIN UPDATE way SET topo_geom = topology.toTopoGeom(st_force2d(line), 'way_topo', 1) WHERE id = r.id<http://r.id>; EXCEPTION WHEN OTHERS THEN RAISE WARNING 'Loading of record % failed: %', r.id<http://r.id>, SQLERRM; END; END LOOP; UPDATE world_grid set last_update = now() where gid=tile_id; return 'OK'; END $BODY$ LANGUAGE plpgsql VOLATILE COST 100; Thanks Marc _______________________________________________ postgis-users mailing list [email protected]<mailto:[email protected]> http://lists.osgeo.org/cgi-bin/mailman/listinfo/postgis-users _______________________________________________ postgis-users mailing list [email protected] http://lists.osgeo.org/cgi-bin/mailman/listinfo/postgis-users _______________________________________________ postgis-users mailing list [email protected] http://lists.osgeo.org/cgi-bin/mailman/listinfo/postgis-users _______________________________________________ postgis-users mailing list [email protected] http://lists.osgeo.org/cgi-bin/mailman/listinfo/postgis-users
