"Pavel Stehule" <pavel.stehule@gmail.com> writes:
> look again
> select c as foo from tab ...
> select fce(c as foo) from tab ...
> when you use AS as param names specification, you change meaning of
> some construct via used context?
Uh, what's your point? AS changes the meaning too. For example in
select foo, bar from (select c as foo, d as bar from ...) ss;
we are using AS to specify the names seen by the outer select.
This seems to me to be quite a close parallel to attaching names
to function parameters.
regards, tom lane