Re: BUG #12589: Poor randomness from random() with some seeds; poor resolution - Mailing list pgsql-bugs

From Tom Lane
Subject Re: BUG #12589: Poor randomness from random() with some seeds; poor resolution
Date
Msg-id 10225.1421722783@sss.pgh.pa.us
Whole thread Raw
In response to Re: BUG #12589: Poor randomness from random() with some seeds; poor resolution  (Pedro Gimeno <pgsql-004@personal.formauri.es>)
Responses Re: BUG #12589: Poor randomness from random() with some seeds; poor resolution  (Pedro Gimeno <pgsql-004@personal.formauri.es>)
List pgsql-bugs
Pedro Gimeno <pgsql-004@personal.formauri.es> writes:
> Tom Lane wrote, On 2015-01-19 16:22:
>> This is not a bug; it's a feature request, and a rather poorly
>> grounded one at that.

> It's a purportedly random sequence that turns out not to be random, with
> not even a caveat in the manual. That's a bug.

It is absolutely arguable that this is a glibc bug, so I encourage you
to submit a bug report to them and see what happens.  However, Postgres'
random() function is clearly documented to be just a thin layer over the
platform's random() function:

    The characteristics of the values returned by random() depend on
    the system implementation.

That seems to me to be a sufficient "caveat".

            regards, tom lane

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