Atsushi Ogawa <atsushi.ogawa@gmail.com> writes:
> (2)About processing when column identifier of SET clause is specified
> like 'AAA.BBB'. 'AAA' is a composite column now. When an alias for
> target table is supported, 'AAA' is a composite column or a table.
> How do we distinguish these?
You don't, which is why you can't put an alias on a SET target.
Increasing the reserved-ness of SET isn't real attractive either.
regards, tom lane