"Pavel Stehule" <pavel(dot)stehule(at)gmail(dot)com> writes:
> I understand. So every smallint should be call with casting?
A long time ago we tried to make small integer literals be interpreted
as int2 initially, instead of int4, and the attempt failed rather
spectacularly. (It broke most of the regression tests, IIRC, in ways
that suggested that many client applications would have problems too.)
Perhaps PG's type system has matured to the point where it'd work better
now, but I'm not really interested in trying it. I don't see very much
point in declaring functions to take smallint rather than int anyway...
regards, tom lane