Sandro Santilli (Keybit) est un des plus anciens core développeur de PostGIS et GEOS.
Après plusieurs années sur d'autres projets OpenSource il revient sur ces technos, et c'est tant mieux ! Son avis technique fait toujours office de référence, et il vient de rejoindre le PSC PostGIS.
Il est le principal développeur du support topologique de PostGIS.
Topology support has been available in PostGIS as a draft since version 1.1.0, but remained in the shadow until a recent use case by the Italian Tuscany Region brought it back under the light and allowed improving its usability and functionality.
In PostGIS 2.0, topology is a core component with its place in build scripts, documentation, regression testsuite, tickets management system. Beside better integration, changes since the draft of 2006 include improved performances, bug fixes, more functions for topology construction and editing, topological GML export.
The PostGIS topology allows to model topologically defined feature layers in a standardized way so to enable better interoperability with other tools (import/export, visualization, analysis…). For example there's work in progress on a GDAL driver to import topological GML directly into PostGIS.
This session will give an overview of the model from conceptual to physical, describe its advantages and disadvantages over a simple features model and will illustrate the existing and planned support functions, with examples of transition from one model to the other.