Re: Functions to return random numbers in a given range

On Tue, 27 Feb 2024 at 17:33, Dean Rasheed <dean(dot)a(dot)rasheed(at)gmail(dot)com> wrote:
>
> On Sat, 24 Feb 2024 at 17:10, Tomas Vondra
> >
> > I did a quick review and a little bit of testing on the patch today. I
> > think it's a good/useful idea, and I think the code is ready to go (the
> > code is certainly much cleaner than anything I'd written ...).
>

Based on the reviews so far, I think this is ready for commit, so
unless anyone objects, I will do so in a day or so.

As a quick summary, this adds a new file:

src/backend/utils/adt/pseudorandomfuncs.c

which contains SQL-callable functions that access a single shared
pseudorandom number generator, whose state is private to that file.
Currently the functions are:

random() returns double precision [moved from float.c]
random(min integer, max integer) returns integer [new]
random(min bigint, max bigint) returns bigint [new]
random(min numeric, max numeric) returns numeric [new]
random_normal() returns double precision [moved from float.c]
setseed(seed double precision) returns void [moved from float.c]

It's possible that functions to return other random distributions or
other datatypes might get added in the future, but I have no plans to
do so at the moment.

Regards,
Dean