On Wed, Apr 23, 2008 at 3:27 AM, Dylan Beaudette <[EMAIL PROTECTED]> wrote:
> On Tuesday 22 April 2008, Paul Ramsey wrote: > > The operators (@, &&, etc) all work on bounding boxes. The functions > > all work on full geometries. It is possible for geometries to satisfy > > bounding box containment while not satisfying full geometric > > containment, hence your discrepancy. > > > > P. > > Thanks for the clarification. > > Does it make sense any more to use one of the &&, @, etc. operators to > pre-filter geometries, or do the ST_ functions take care of that in call > cases? i.e. can you think of any cases where it would still be a good idea > to > use something like > > select st_intersection(a,b) > from a, b > on a && b ; > > Thanks, > > Dylan In the past, that was the recommended approach. With the ST_ prefixed functions, PostGIS will automatically include the bounding box operators for pre-filtering. It's just that good. -- Mark
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