Re: numeric cast oddity

Sim Zacks <sim@compulab.co.il> writes:
> If I replace that column with -1::numeric(20,4) or - (1::numeric(20,4))
> the type that goes to the view is numeric without any scale or precision
> and then I get an error that I cannot change the column type.

You've still got the order of operations wrong.
    (-1)::numeric(20,4)
is known to have typmod (20,4), because the cast operation enforces it.
    - (1::numeric(20,4))
is not known to have any particular typmod --- it actually does fit in
(20,4), of course, but that fact depends on the detailed behavior of the
minus operator, which is not known to the type machinery.

            regards, tom lane