Thomas Lockhart wrote:
>
> > > ... represent general subqueries or intermediate queries in the
> > > parse tree.
> > Maybe it's time to bite the bullet and do it. You have any thoughts
> > on what the representation should look like?
>
> I was hoping you would tell me ;)
>
> I don't have a good feel for the current parse tree (which of course
> hasn't kept me from fooling around with it). But I'll definitely need
> something extra or different to implement outer joins. If I were
> keeping everything else the same, I was thinking of propagating a
> "join expression" into the planner/optimizer in the same area as the
> existing qualification nodes. One of the differences would be that the
> JE marks a node around which the optimizer is not allowed to reorder
^^^^^^^^^^^^^^^^^^^^^^^^^
> the plan (since outer joins must be evaluated in a specific order to ^^^^^^^^
> get the right result). But I could just as easily represent this as a
And this is what we need to have subqueries in FROM!..
(One a great thing which I want to have so much -:))
> subquery node somewhere else in the parse tree.
Vadim