Re: Understanding Datum

Nick Raj <nickrajjain@gmail.com> writes:
> In postgres, typedef uintptr_t Datum
> Datum is getting value from PG_GETARG_POINTER(1);
> But, now problem is how would i know the type of PG_GETARG_POINTER(1)
> (postgres internally pass this argument) to figure out datum type?

Datum does not carry any type information, only a value.  Functions are
typically coded to know their input types a priori.  If you want to
write code that is not type-specific then you'd better be passing around
type OIDs as well as values.

            regards, tom lane