[postgis-users] topology overlapping of edges

Andrea Peri aperi2007 at gmail.com
Fri Sep 28 23:41:41 PDT 2012

>* For my import I will update the pointers of edges my own, could you*>* Sandro point me to*>* specifications of  next_*_edge.*

I guess shoulkd better spend time to optimize the actual ISO function
rather than think to do own low level function.

The controls to do a right ISO topology are many and skipping them to have
fast load mean to have a not really topological
Also there is never in the topology table to maintain really the topology.

The correctness of topology is all on the ISO functions.

Another point is that often 8really often I guess) the user think to have a
set topological.
But instead it is not so.

As example.
The only product I know capable to produce a really topological set
is arcinfo -workstation version (with coverages) or oracle with topology

No other product is capable of this.

please note che rules of arcgis don't work on coverages so they don't grant
toe really topology face-edge-node.

So If an user write own function to load the postgis topology tables.
And it's dataset is not really topology and it write more fast routine
skipping some complex controls to be faster.
It will produce simply some tables anemd topolgycal but not really

And so grows the caos.

So who like write a truly topological load system should get and follow the
ISO specs.
The actually version of postgis topology is write followinfg the ISO specs
row by row.


Andrea Peri
. . . . . . . . .
qwerty àèìòù
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.osgeo.org/pipermail/postgis-users/attachments/20120929/c80acf99/attachment.html>

More information about the postgis-users mailing list