Re: Re: [GENERAL] +/- Inf for float8's

Thomas Lockhart writes:

> > So, anyone have any ideas what NaN would be useful for? Especially given
> > we have NULL available, which most (non DB) numeric applications don't.
> 
> Hmm. With Tom Lane's new fmgr interface, you *can* return NULL if you
> spot a NaN result. Maybe that is the best way to go about it; we'll
> stipulate that NaN and NULL are equivalent. And we'll further stipulate
> that if you are messing with NaN then you deserve what you get ;)

I beg to differ, this behaviour would not be correct. Instead, this should
happen:

NULL < NULL    => NULL
NULL < 1.0    => NULL
NULL < Nan    => NULL
1.0 < NULL    => NULL
1.0 < NaN    => false
NaN < NULL    => NULL
NaN < 1.0    => false

Then all the NaN's sort either all first or all last before or after the
NULLs.


-- 
Peter Eisentraut                  Sernanders väg 10:115
peter_e@gmx.net                   75262 Uppsala
http://yi.org/peter-e/            Sweden