Re: Why is NULL = unbounded for rangetypes?

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От Jeff Davis
Тема Re: Why is NULL = unbounded for rangetypes?
Дата
Msg-id 1377825789.18255.2.camel@sussancws0025
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Ответ на Re: Why is NULL = unbounded for rangetypes?  (Andreas Joseph Krogh <andreak@officenet.no>)
Ответы Re: Why is NULL = unbounded for rangetypes?  (Andreas Joseph Krogh <andreak@officenet.no>)
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On Tue, 2013-07-09 at 10:45 +0200, Andreas Joseph Krogh wrote:
> I would expect the queries above to return FALSE and have to use
> INFINITY to have them return TRUE. I don't understand what you mean by
> ranges not allowing either bound to be NULL as it seems to be the case
> (as in "it works").

Although passing NULL to the constructor works, it does *not* create a
range where one bound is NULL. It actually creates an unbounded range;
that is, a range where one bound is infinite.

NULL semantics are far too confusing to be useful with ranges. For
instance, if ranges did support NULLs; the queries you mention would
have to return NULL, not FALSE.

Regards,
    Jeff Davis




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