Pedro Gimeno <pgsql-004(at)personal(dot)formauri(dot)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