[postgis-devel] Should EMPTY be spatially equal to self ?

[Sandro Santilli]

On Fri, Jan 13, 2012 at 01:23:19PM +0100, Havard Tveite wrote:
> On 1/13/2012 12:48 PM, Sandro Santilli wrote:
> >On Fri, Jan 13, 2012 at 11:01:21AM +0100, Havard Tveite wrote:
> >>1) ST_Equals can be used as a spatial join predicate.
> >>2) An empty geometry has no location.
> >>
> >>Therefore, I think that ST_Equals(empty,empty) should
> >>not return true and not return false, but NULL.
...
> I was only trying to contribute to the discussion / reasoning
> in order to find the most correct and/or logical solution.

Ok, so why do you think ST_Equals(empty,empty) should not be true ?
ST_Equals test two geometries for occupying the exactly same space.

--strk; 

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