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
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