On Tue, Jun 16, 2020 at 11:50 AM Dean Rasheed <dean.a.rash...@gmail.com> wrote:
> On Tue, 16 Jun 2020 at 10:09, Juan José Santamaría Flecha > <juanjo.santama...@gmail.com> wrote: > > > > It is defined as NaN (or undefined), which is not in the realm of > integer numbers. You might get a clear idea of the logic from [1], where > they also make a case for the error being ERRCODE_DIVISION_BY_ZERO. > > > > [1] http://mathforum.org/library/drmath/view/60851.html > > > > Hmm, I think ERRCODE_DIVISION_BY_ZERO should probably be reserved for > actual division functions. > > With [1], we could return 'Infinity', which would be more correct from > a mathematical point of view, and might be preferable to erroring-out > in some contexts. > > [1] > https://www.postgresql.org/message-id/606717.1591924582%40sss.pgh.pa.us Returning division-by-zero would be confusing for the user. I think that out-of-range would be a reasonable solution for "FUNCTION factorial(integer) RETURNS integer", because it could only return an integer when the input is a positive integer, but for "FUNCTION factorial(integer) RETURNS numeric" the returned value should be 'NaN' without error. Regards, Juan José Santamaría Flecha
