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Subject: Re: [HACKERS] Re: [GENERAL] +/- Inf for float8's From: Peter Eisentraut <peter_e@gmx.net> Date: Sun, 20 Aug 2000 00:33:49 +0200 (CEST) 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. ===