[postgis-devel] Boxes cache and type (was: Caching Double-based Boxes)

[Sandro Santilli]

On Fri, Nov 25, 2011 at 10:38:47AM +0100, Nicklas Avén wrote:

> In my example I posted in last post, the difference is 0.3 meters! It is
> no microunits we are talking about.

What's the extent of your dataset for 0.3 meters to be so important ?
What projection ?

> The result is also that the ordering is wrong. You don't get the nearest
> point when you expect it. 

Is 0.3 meters important when looking for nearest point ?
What's the use case ? Find closest glasses to a bottle on
the table in an appartment of a City ?

> I think it is more a question of being aware of it and informing that
> PostGIS knn queries might give the wrong answer even if Postgresql knn
> will give the right answer on the same dataset, just like the much
> slower st_distance way of doing it. 

A NOTE in the manual would be enough to me.

--strk;

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