Re: logical column position

Andreas Pflug <pgadmin@pse-consulting.de> writes:
> Maybe my proposal wasn't clear enough:
> Just as an index references a pg_class entry by it's OID, not some value 
> identifying it's physical storage, all objects might continue 
> referencing columns by attnum.

That's exactly the same thing I am saying.  Your mistake is to assume
that this function can be combined with identification of a (changeable)
logical column position.  It can't.  Changeability and immutability are
just not compatible requirements.
        regards, tom lane