Re: 38.10.6. Composite-Type Arguments C-language function code demo works for int, but not for numeric.

jian he <jian(dot)universality(at)gmail(dot)com> writes:
> column "salary" int data type works fine. But it does not work if the
> "salary" column data type is numeric.

Your problem is that numeric is not a primitive C type:

> PG_RETURN_BOOL(DatumGetNumericCopy(salary) > limit);

That is comparing two pointers-to-numerics, not the values of
the numerics. You'd need to invoke numeric_cmp() if you
want a sensible result.

regards, tom lane