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<div dir="ltr" data-setdir="false">Ufff, I also wanted this time ago, and still want it! is just there is some things to take care.</div><div dir="ltr" data-setdir="false"><br></div><div dir="ltr" data-setdir="false">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 it</div><div dir="ltr" data-setdir="false">2. 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.</div><div dir="ltr" data-setdir="false">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.</div><div dir="ltr" data-setdir="false"><br></div><div dir="ltr" data-setdir="false">From my perspective the ideal is have a Standard v2, and be implemented on PGRouting instead of Postgis.</div><div dir="ltr" data-setdir="false"><br></div><div dir="ltr" data-setdir="false">Thx!<br></div><div><br></div>
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El martes, 19 de noviembre de 2024, 11:23:04 a. m. GMT-3, Pierre HARDY <pierre.hardy5@gmail.com> escribió:
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<div><div id="yiv0056779421"><div dir="ltr"><div dir="ltr"><div dir="ltr"><div dir="ltr"><div dir="ltr"><div dir="ltr"><div dir="ltr"><div>Hello PostGIS devs,</div><div><br></div><div>It seems that "postgis_topology" extension does not support topology-network approach.</div><div>Here are my sources:</div><div><ol><li>What is topology-network: <a rel="nofollow noopener noreferrer" target="_blank" href="https://www.gaia-gis.it/fossil/libspatialite/wiki?name=topo-intro">https://www.gaia-gis.it/fossil/libspatialite/wiki?name=topo-intro</a></li><li>Source no1 indicating that Postgis does not support topology-network approach: <a rel="nofollow noopener noreferrer" target="_blank" href="https://gis.stackexchange.com/questions/122636/prevent-postgis-topology-from-splitting-edges-on-line-insert">https://gis.stackexchange.com/questions/122636/prevent-postgis-topology-from-splitting-edges-on-line-insert</a></li><li>Source no2 indicating that Postgis does not support topology-network approach: <a rel="nofollow noopener noreferrer" target="_blank" href="https://terragis.net/docs/other/MASTERING_POSTGIS.pdf">https://terragis.net/docs/other/MASTERING_POSTGIS.pdf</a> => p253</li></ol></div></div></div></div><blockquote style="margin:0px 0px 0px 40px;border:none;padding:0px;"><blockquote style="margin:0px 0px 0px 40px;border:none;padding:0px;"><div dir="ltr"><div dir="ltr"><div dir="ltr"><div><div>"Before we start working with topology, we need to discuss the key concepts behind the
PostGIS topological data model. PostGIS topology implementation is based on ISO standard
13249 - Information technology - Database languages - SQL multimedia and application packages -
Part 3: Spatial. The standard name is often abbreviated as ISO SQL/MM. This standard
defines two data models for topology: TopoGeometry and TopoNetwork; PostGIS
implements only the former."</div></div></div></div></div></blockquote></blockquote><blockquote style="margin:0px 0px 0px 40px;border:none;padding:0px;"><blockquote style="margin:0px 0px 0px 40px;border:none;padding:0px;"><div dir="ltr"><div dir="ltr"><div dir="ltr"><div><br></div></div></div></div></blockquote></blockquote><div dir="ltr"><div dir="ltr"><div dir="ltr"><div>I could verify this by testing on a basic local setup with QGIS and <b>Postgis version 3.3</b>. </div><div>I guess this feature was not added since. </div><div><br></div><div>I did not found any issues regarding this missing feature.</div><div><br></div><div>Is an issue already openned to request this new feature or should I create one ?</div><div><br></div><div>Best regards,</div><span class="yiv0056779421gmail_signature_prefix">-- </span><br><div dir="ltr" class="yiv0056779421gmail_signature">Pierre HARDY<br></div></div></div></div></div></div></div></div>
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