[postgis-devel] Multi-D Indexing and Serialized Form

Chris Hodgson chodgson at refractions.net
Mon Jul 13 14:44:53 PDT 2009

Oh, I understand, you're not talking about what dimension of bbox gets 
stored in the index, you're talking about how many dimensions the bbox 
in the geometry object is... in which case, I think you're straight-line 
solution seems to make the most sense. Otherwise it is an additional 
parameter that you have to specify when you create your geometry column 
- how many dimensions is the bbox.


Paul Ramsey wrote:
> Yes, if we are willing to re-calculate the full bounding box for
> comparison purposes, every time we need it. For large geometries, this
> is a bad trade-off. But that speaks again to simply calculating the
> fully dimensional bbox. We don't currently have a very clever use of
> the clever "optional bbox" trick dave baked into the initial revision,
> but that clever trick gets us a long way if we don't use bboxes at all
> for smaller geometries that we are fine with calculating the bbox for
> every time.
> O

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