Re: OUTER joins

Поиск
Список
Период
Сортировка
От Bruce Momjian
Тема Re: OUTER joins
Дата
Msg-id 199903090325.WAA16653@candle.pha.pa.us
обсуждение исходный текст
Ответ на Re: OUTER joins  ("Thomas G. Lockhart" <lockhart@alumni.caltech.edu>)
Список pgsql-hackers
> > > Hadn't thought about it, other than figuring that implementing the
> > > equi-join first was a good start. There is a class of outer join 
> > > syntax (the USING clause) which is implicitly an equi-join...
> > Not that easy.  You don't automatically get a mergejoin from an
> > equijoin.  I will have to force outer's to be either mergejoins, or
> > inners of non-merge joins.  Can you add code to non-merge joins in the
> > executor to throw out a null row if it does not find an inner match 
> > for the outer row, and I will handle the optimizer so it doesn't throw 
> > a non-conforming plan to the executor.
> 
> So far I don't have enough info in the parser to get the
> planner/optimizer going. Should we work from the front to the back, or
> should I go ahead and look at the non-merge joins? It's painfully
> obvious that I don't know anything about the middle parts of this to
> proceed without lots more research.

We need to do phone or IRC to discuss this. Let me know when.

--  Bruce Momjian                        |  http://www.op.net/~candle maillist@candle.pha.pa.us            |  (610)
853-3000+  If your life is a hard drive,     |  830 Blythe Avenue +  Christ can be your backup.        |  Drexel Hill,
Pennsylvania19026
 


В списке pgsql-hackers по дате отправления:

Предыдущее
От: Bruce Momjian
Дата:
Сообщение: Re: [HACKERS] Developers globe
Следующее
От: "Thomas G. Lockhart"
Дата:
Сообщение: Re: [HACKERS] What's happened with 1942