[postgis-users] Difference between @ and ST_WITHIN/ST_CONTAINS

[Mark Leslie]

On Wed, Apr 23, 2008 at 3:27 AM, Dylan Beaudette <dylan.beaudette at gmail.com>
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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