Re: [PATCH] Introduce array_shuffle() and array_sample()

On Thu, 21 Jul 2022 at 12:15, Martin Kalcher
<martin(dot)kalcher(at)aboutsource(dot)net> wrote:
>
> I agree that we should use pg_prng_uint64_range(). However, in order to
> achieve interoperability with setseed() we would have to use
> drandom_seed (rather than pg_global_prng_state) as rng state, which is
> declared statically in float.c and exclusively used by random(). Do we
> want to expose drandom_seed to other functions?
>

Ah, I didn't realise that setseed() and random() were bound up so
tightly. It does feel as though, if we're adding more user-facing
functions that return random sequences, there ought to be a way to
seed them, and I wouldn't want to have separate setseed functions for
each one.

I'm inclined to say that we want a new pg_global_prng_user_state that
is updated by setseed(), and used by random(), array_shuffle(),
array_sample(), and any other user-facing random functions we add
later.

I can also see that others might not like expanding the scope of
setseed() in this way.

Regards,
Dean