pgsql-bugs(at)postgresql(dot)org writes:
> SELECT MOD(RANDOM(),1.0);
> ERROR: Function mod(double precision, numeric) does not exist
> Unable to identify a function that satisfies the given argument types
> You may need to add explicit typecasts
> I was able to work around it by casting RANDOM() to NUMERIC.
This is not a bug, but an intentional change: float->numeric isn't an
implicit cast anymore.
regards, tom lane