[postgis-devel] Caching Double-based Boxes

[Mark Cave-Ayland]

On 25/11/11 19:16, Paul Ramsey wrote:

> KNN is a red herring: we're not going to change the index itself off
> of floats; KNN ordering on boxes is always going to be a huge
> approximation anyways.
>
> What I'm missing here is any feedback on how my experimental branch
> *works*, namely, is it still fast enough?
>
> http://svn.osgeo.org/postgis/spike/pramsey/doublebox
>
> Without Mark here to sing the praises of double boxes, it feels like
> nobody cares enough for this to move forward, except maybe strk,
> though he has mostly patched up the implementation problems with boxes
> not being determinstic by sticking box rounding in various locations
> around the code base. Which is too bad, because I spent a day on it.
> But it's a hard-to-quantify improvement. It makes some things more
> clear, since the lwgeom->bbox is more consistent. It'll also make the
> ST_Extent aggregate marginally faster (because ST_Extent() can use the
> cached boxes without guilt).

(goes and reads long email thread)

Gosh. Looks like I picked the wrong time to go and have a nice long 
weekend away in the country - I'll try my best to pick up on various 
points though.


ATB,

Mark.

-- 
Mark Cave-Ayland - Senior Technical Architect
PostgreSQL - PostGIS
Sirius Corporation plc - control through freedom
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