Re: some random() clarification needed

Thanks!
makes it clearer :-)
its not that obvious to guess the consequences of the "volatile" behaviour.
regards,

Marc MILLAS
Senior Architect
+33607850334
www.mokadb.com

On Wed, Jul 15, 2020 at 1:53 AM David Rowley <dgrowleyml(at)gmail(dot)com> wrote:

> On Wed, 15 Jul 2020 at 04:01, Marc Millas <marc(dot)millas(at)mokadb(dot)com> wrote:
> > your answer helps me understand my first problem.
> > so, I rewrote a simple loop so as to avoid the "volatile" behaviour.
>
> Not sure what you're trying to do with the plpgsql, but you can just
> escape the multiple evaluations by putting the volatile function in a
> sub-select with no FROM clause.
>
> SELECT ... FROM ... WHERE id = (SELECT ceiling(random()*2582));
>
> Or the more traditional way to get a random row is:
>
> SELECT ... FROM ... WHERE id BETWEEN 0 AND 2585 ORDER BY random() LIMIT 1;
>
> David
>