From: | gateley(at)jriver(dot)com |
---|---|
To: | Joe Conway <joseph(dot)conway(at)home(dot)com> |
Cc: | "Dr(dot) Evil" <drevil(at)sidereal(dot)kz>, pgsql-general(at)postgresql(dot)org |
Subject: | Re: Still wondering about random numbers... |
Date: | 2001-08-07 16:41:36 |
Message-ID: | 3B701A40.B0EC1685@jriver.com |
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Lists: | pgsql-general pgsql-patches |
Joe Conway wrote:
>
> > I am running on OpenBSD and Linux, both of which have
> > cryptographic-quality RNGs built in. When I call RANDOM() in PG, do I
> > get the old C library random numbers, which are not very random, or do
> > I get high-quality random numbers from the crypto-RNG that's built in?
> > Any sugestions for getting high-quality random numbers?
>
> Looking through the source, I find:
> result = ((double) random()) / ((double) MAX_RANDOM_VALUE);
The random() function returns better (good?)
random numbers. The rand() function returns poor
random numbers. random() also depends on how
much state it is initialized with (and may or may
not be based on /dev/random, I don't know).
j
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