On Sat, 2004-07-17 at 14:30, Tom Lane wrote:
> David Newall <davidn-postgres@rebel.net.au> writes:
> > select * from a join b optimises differently to select * from a join
> > (select * from b) as b
>
> The above claim is provably false. Now, if you throw in some more
> tables and sprinkle in a LEFT JOIN instead of just JOIN here and there,
> you can get different plans --- but the semantics are not necessarily
> the same, either.
You're right. It's select * from a left join b left join c that
optimises differently to select * from a left join (select * from b left
join c). I was clumsy with my language but I think my meaning was clear
within the context of this thread. Anyway, back to my point: I'd like
to use a view but I can't because it's too slow, and that's a pity.