Alexandre,
Your straight forward method is the best.
PostGIS takes care of optimization using rectangular bounding boxes.
Union function works best if you use it as an aggregate function. In OGR,
you can use OGRGeometry::UnionCascaded() by passing a OGRGeometryCollection
object to it.
On Fri,
Hi,
I am using GDAL/OGR to find the links under a set of towns, on the whole
France territory.
My links and my towns are stored on a Postgis database.
For the moment I use the most precise request I can:
- I make a union of all the polygons of the towns I am interested in
- I send a request
