[postgis-users] Any functions for validating topology of areas, lines/points and/or routes?

[Stefan Keller]

Dear all

I’m preparing an introductory course about GIS and want to collect
topology functions. We’re evaluating QGIS and PostGIS and have to
be prepared that the functionality will be compared to ArcGIS/
ArcEditor Geodatabase Topology (called topology rules there).

Thus my question: Can anyone point me to topology functions,
most probably implements as stored procedures (pl/pgsql) and
triggers (rules)?

I’ve compiled following “topology types” so far:
* Area topology cleaning: Eliminating sliver polygons, overshoots,
  undershoots (polygon topology, same polygon class).
* Polygons are non-overlapping (polygon topology, same polygon class).
* Polygons are inside other polygons (polygon topology, two different
  polygon classes).
* Line topology cleaning: Snapping close endpoints
  (vertex-vertex/route topology).
* Routes that share vertices (vertex-vertex/route topology, same
  line class).
* Line objects that share (inner) endpoints (node-vertex topology,
  same line class).
* Line objects that are “connected to” point objects at their
  (outer/inner) endpoints (node-node topology, line and point classes).
* Point objects that share points along line objects (node-vertex
  topology, line and point classes).

Pls. consider "are" (validation) as place holder to be also "should not"
(validation) or "should be snapped to" (cleaning).

Regards, S.