Re: [GENERAL] Re: random() function produces wrong range

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От Roland Roberts
Тема Re: [GENERAL] Re: random() function produces wrong range
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Msg-id m2n1iuz1q6.fsf@tycho.rlent.pnet
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Ответ на random() function produces wrong range  (Tom Lane <tgl@sss.pgh.pa.us>)
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-----BEGIN PGP SIGNED MESSAGE-----

>>>>> "Tom" == Tom Lane <tgl@sss.pgh.pa.us> writes:

    Tom> Actually the odds are far better than that.  If the range is
    Tom> 2^31-1 then only about 2^-16th of the outputs should be less
    Tom> than 2^15.  So ten probes gives you a failure probability of
    Tom> about 2^-160 not 2^-10.

Oops, 2^16 != 2^32 / 2.

So a dynamic test is not only possible but wouldn't cost to much at
configure time.

roland
- --
               PGP Key ID: 66 BC 3B CD
Roland B. Roberts, PhD                    Unix Software Solutions
roberts@panix.com                      76-15 113th Street, Apt 3B
rbroberts@acm.org                          Forest Hills, NY 11375

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