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

[Havard Tveite]

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.
>> What would be the consequences of that?
>
> Do you really use ST_Equals as a join predicate ?
> It'd be pretty overkill.

No, I don't normally use ST_Equals as a spatial join predicate.
I was only trying to contribute to the discussion / reasoning
in order to find the most correct and/or logical solution.

Håvard