[postgis-users] PostGIS Capabilities

[Paul Ramsey]

On Tuesday, February 24, 2004, at 04:35 AM, Markus Schaber wrote:

> HIt seems that such distance operation queries still involve a 
> sequential
> scan over the whole table. So one better combines this query with an
> bounding box that is &&'ed to the geometries to make use of the index.

Yes, always.

> The same Problem appears when searching the nearest Object, PostGIS
> cannot make any use of spatial indices in this case, so one has to
> interate with growing bounding boxes...

Indexing a "nearest" query is quite a nasty business if you think about 
it.

P.


      Paul Ramsey
      Refractions Research
      Email: pramsey at refractions.net
      Phone: (250) 885-0632