Re: [GRASS-dev] Grass to postgis topology export performance
Hey, thanks for your answer. I uploaded a new test file of about the same number of line (32k), also already topological (meaning in theory there is no need to split line, just compute node, neighbourhood, and faces). It is here : http://trac.osgeo.org/postgis/ticket/2695 About the command I used, I followed the wiki page on grass, I tried both suggested methods: I issued those with grass 7 svn, on windows, using the GUI to have a terminal. As I stated grass is extremely fast to build topology, and then the export to postgis topology is already faster than using pure postgis topology, but yet surprisingly slow compared to the grass internal. v.in.ogr dsn=PG:host=localhost port=5433 dbname=street_gen user=postgres password=?? layer=bdtopo.route out=test_postgis_import v.out.postgis -l -2 input=route@T051 dsn=PG:host=localhost dbname=street_gen port=5433 user=postgres password=?? olayer=test_layer -t v.external.out dsn=PG:host=localhost dbname=street_gen port=5433 user=postgres password=?? options=topology=yes format=PostgreSQL v.in.ogr dsn=\route_utf8.shp -t Cheers, Rémi-C 2014-04-01 13:42 GMT+02:00 Martin Landa landa.mar...@gmail.com: Hi, 2014-04-01 11:43 GMT+02:00 Rémi Cura remi.c...@gmail.com: Grass GIS is very fast to construct a topology over vectors (5 secs), and then surprisingly slow in exporting this model to Postgis topology (145 sec). Is there a perticular reason for this? I tried to read the code, but couldn't get to the sql querries. Also, in a more prospective way, could Grass import from geometry (shapefile for example) then export to postgis topology be isolated (into an exe or a lib?). could you post exact commands you run, or some sample data to play with. Thanks, Martin ___ grass-dev mailing list grass-dev@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-dev
[GRASS-dev] Grass to postgis topology export performance
Hello everybody, I'm an active user of Postgis and postgis topology. Currently Postgis topology is slow, so I did a benchmark of other available options (see at the end). Grass GIS is very fast to construct a topology over vectors (5 secs), and then surprisingly slow in exporting this model to Postgis topology (145 sec). Is there a perticular reason for this? I tried to read the code, but couldn't get to the sql querries. Also, in a more prospective way, could Grass import from geometry (shapefile for example) then export to postgis topology be isolated (into an exe or a lib?). Many Thanks, Cheers, Rémi-C Here is a little comparison : (32k polylines,21k unique points, already 'topological'( no need to cut the lines) ,with a lot of attributes) Postgis Topology Postgis Topology (addtopogeom) : 700+ sec for 10k lines, (??about 1600 sec for 32k lines??) Postgis Topology (addlinestring) : 240+ sec for 10k lines, (??about 780 sec for 32k lines??) Postgis Topology (addnode, addedge) : 80sec for 10 k lines (??about 260sec for 32k lines??) Grass Gis 7 : Importing everything : 10 sec Importing only geom (no attributes) : 5 sec Importing everything then Exporting all topologies to postgis topology : 150 sec Declare postgis topo as external source and fill it with shapefile : 145 sec Geos : (upper bound measured trough st_polygonize) ST_Polygonize on everything (aggregates on 32k lines) : about 5 sec TopoJSON (according to previous thread : postgis topology/60 ) Importing geometry (extrapolated) : about 30 sec? CGAL (half edge, exact kernel) : 4 sec in batch mode (inserting all lines at once) 40min in line by line insertion ___ grass-dev mailing list grass-dev@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-dev
Re: [GRASS-dev] Grass to postgis topology export performance
Hi, 2014-04-01 11:43 GMT+02:00 Rémi Cura remi.c...@gmail.com: Grass GIS is very fast to construct a topology over vectors (5 secs), and then surprisingly slow in exporting this model to Postgis topology (145 sec). Is there a perticular reason for this? I tried to read the code, but couldn't get to the sql querries. Also, in a more prospective way, could Grass import from geometry (shapefile for example) then export to postgis topology be isolated (into an exe or a lib?). could you post exact commands you run, or some sample data to play with. Thanks, Martin ___ grass-dev mailing list grass-dev@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-dev
