Re: [HACKERS] Another reason to redesign querytree representation

Bruce Momjian <maillist(at)candle(dot)pha(dot)pa(dot)us> writes:
> Did you want to do the change for UNION, or were you just suggesting it
> be done? I can easily add it to the TODO list.
> Done:

> * redesign UNION structures to have separarate target lists.

Actually, it's not so much UNION that's busted as it is INSERT.
The parser problems could be dealt with by having a two-level structure
for INSERT ... SELECT ..., so that the targetlist for the eventual
INSERT could be described without changing the semantics of the
underlying SELECT.

There might be other extensions needed for rules (paging Jan...) but
as far as what I've been looking at goes, the TODO entry could be just

* redesign INSERT ... SELECT to have two levels of target list.

Thomas, what do you think is needed for outer joins?

regards, tom lane