[postgis-devel] ST_Covers AND &&

Sandro Santilli strk at keybit.net
Tue Mar 1 02:05:01 PST 2011


On Tue, Mar 01, 2011 at 11:02:19AM +0100, Sandro Santilli wrote:
> I was thining, shouldn't ST_Covers use @ operator rather than && ?
> If A convers B then B bounding box must be _contained_ in A bounding box.
> Right ?

Just to add: such check is already performed by the C version
of ST_Contains, in a short-cut. But using operator @ should do
this while scanning the index w/out the need to fetch full
geometry.

I haven't performed performance comparisons yet.

--strk; 

  ()   Free GIS & Flash consultant/developer
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