[postgis-devel] What's the point of this exercise in intersects?

[Obe, Regina]

Mark,
>  Why can't you be happy with bliss?
I feel a little bit more blissful now.  Thanks Mark.

Eternal Bliss is so boring.  Life is about misery and overcoming it or
making yourself more miserable.  It is all about having non-zero
derivatives :)

>  As for the generated geometries, they are automatically generated in
a
> number of cases, which are documented somewhere in the code.  I don't
> recall what they all were were, but they included such vague cases as,
> 'sufficiently complex geometries,' as well as some quite specific
ones,
> such as 'never on points'.

Hmm so in these cases I presume this redundancy may be useful?  Although
in these cases do 
we make sure to add a bbox to the geometry.  Looking at the comment of
the code - it seems to suggest
the BBOX short-circuit would happen only if there already existed a bbox
attached to the geometry, but I am
not sufficiently skilled in my C reading to determine if the code
completely matches the comment and whether these  generated geometries
you refer to have bboxes.

I'm still questioning how cheap of a call this is though - looks
harmless but you never know.  

Maybe I'll do some large data runs of point in Polys with and without to
see how much of a difference it makes. 

If it were an index call, it would be cheap for sure, but
its not, so I can only assume its worse or at best as good as doing a
non-indexed && on a set of geometries you know will already return true.

Thanks,
Regina
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