Peter Eisentraut <peter_e(at)gmx(dot)net> writes:
> The function current_setting returns 'unset' if a parameter is not set.
> Should it not return null? This is not documented, so I guess this just
> arose out of the implementation, or is this intentional?
That's because SHOW does the same thing. SHOW has a little problem in
that it can't readily show the difference between "null" and an empty
string, so while I find the behavior pretty ugly, I don't have a better
idea.
The question thus is do you want the function behaving differently from
SHOW. Returning NULL is probably better from a programming point of
view, but it'd be inconsistent with the command.
regards, tom lane