[postgis-users] Performance comparison between PostGIS's topology creation and topojson (the module)

Rémi Cura remi.cura at gmail.com
Mon Mar 17 05:36:09 PDT 2014

If you _know_ that your data is topological ready (no intersection).

You can  fill the topology table way faster using set query (rather than
the actual line by line algorithm).

the first step would be to compute the pair of all connected segments, then
extract from it node, node-segment relation and segment-segment relation.
Then fil the face table with bbox from enveloppe of lines

Yet it would require to write some dedicated sql.

Another solution (experimental) would be to load your geometry as a GRASS
GIS vector layer, then use the Grass method (grass 7 only) to convert it to
It should be way way faster.


2014-03-17 12:45 GMT+01:00 Luca Morandini <lmorandini at ieee.org>:

> On 17/03/14 19:51, Sandro Santilli wrote:
>> Topology building speed is a known problem with PostGIS.
>> A few resons I can think of:
> ...
>  That said, see #2610 and #2616 for recent speed improvements
>> with larger topologies.
> D'oh ! Two orders of magnitude slower than a JavaScript program... I hoped
> I had done something very stupid instead.
> Anyway, thanks for the explanations.
> Regards,
> Luca Morandini
> Data Architect - AURIN project
> Melbourne eResearch Group
> Department of Computing and Information Systems
> University of Melbourne
> Tel. +61 03 903 58 380
> Skype: lmorandini
> _______________________________________________
> postgis-users mailing list
> postgis-users at lists.osgeo.org
> http://lists.osgeo.org/cgi-bin/mailman/listinfo/postgis-users
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.osgeo.org/pipermail/postgis-users/attachments/20140317/88949579/attachment-0001.html>

More information about the postgis-users mailing list