Implementation of topology-network approach

[Felipe Matas]

 Ufff, I also wanted this time ago, and still want it! is just there is some things to take care.
1. PGRouting already has Topologies, they do not follow the SQL/MM standard, also do not have the functions for a user be able to use it2. The standard is well defined, is just actually do not define anything else, functions that take advantage of a Network Topology to make them useful, would be great be able to at least list functions for that, the standard is like SF without any spatial operation.3. Personally, I think in this case 2D Points are a very hard constrains, one very useful case for a Network Topology are roads, but in a lot of places int he world, to have a valid Network Topology you need 3D Points, this causes to one of the most useful uses would be impossible.
>From my perspective the ideal is have a Standard v2, and be implemented on PGRouting instead of Postgis.
Thx!

    El martes, 19 de noviembre de 2024, 11:23:04 a. m. GMT-3, Pierre HARDY <pierre.hardy5 at gmail.com> escribió:  
 
 Hello PostGIS devs,
It seems that "postgis_topology" extension does not support topology-network approach.Here are my sources:   
   - What is topology-network: https://www.gaia-gis.it/fossil/libspatialite/wiki?name=topo-intro
   - Source no1 indicating that Postgis does not support topology-network approach:  https://gis.stackexchange.com/questions/122636/prevent-postgis-topology-from-splitting-edges-on-line-insert
   - Source no2 indicating that Postgis does not support topology-network approach:  https://terragis.net/docs/other/MASTERING_POSTGIS.pdf => p253


"Before we start working with topology, we need to discuss the key concepts behind thePostGIS topological data model. PostGIS topology implementation is based on ISO standard13249 - Information technology - Database languages - SQL multimedia and application packages -Part 3: Spatial. The standard name is often abbreviated as ISO SQL/MM. This standarddefines two data models for topology: TopoGeometry and TopoNetwork; PostGISimplements only the former."






I could verify this by testing on a basic local setup with QGIS and Postgis version 3.3. I guess this feature was not added since. 
I did not found any issues regarding this missing feature.
Is an issue already openned to request this new feature or should I create one ?
Best regards,-- 
Pierre HARDY
  
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