[postgis-users] PostGIS topology ISO SQL/MM complete

[Sandro Santilli]

[http://strk.keybit.net/blog/2011/10/14/postgis-topology-iso-sqlmm-complete/]

PostGIS implementation of the ISO SQL/MM Topology-Geometry model
is finally complete [1].

The SQL/MM model [2] is just a portion of the whole topology support [3],
but an important one, including schema definition and functions to create
and populate the schema with primitive components (nodes, edges, faces).

In addition to the base model, PostGIS adds a TopoGeometry [4] data type
for use wherever you would normally use a Geometry type, except the
former will be defined by references to primitive, shared, topological
components.

The work on SQL/MM topology for PostGIS 2.0 was mainly funded by the Land
Management department of the Tuscany Region as part of a larger project
aimed at enhancing effectiveness of free software tools already in use
within the institution for the management of the topographic database.

But more work is needed to make it easier to convert your layers to
topological layers, your Geometries to TopoGeometries [5]. Because I know
you want to generalize your vectors in a topologically consistent way,
don’t you ? And you want to edit the boundaries just once. And do you
want to waste all that space for your triangles ?

Feature freeze for 2.0 will be at the end of November.
Please drop a note if you’d like to help with getting the
enhanced TopoGeometry constructor [5] shipped with it !

[1] http://trac.osgeo.org/postgis/changeset/7886
[2] http://pdfqueen.com/h2-topo-geo
[3] http://postgis.refractions.net/documentation/manual-svn/Topology.html
[4] http://trac.osgeo.org/postgis/wiki/UsersWikiTopoGeometry
[5] http://trac.osgeo.org/postgis/ticket/1017


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