Re: [HACKERS] OUTER joins

Поиск
Список
Период
Сортировка
От Bruce Momjian
Тема Re: [HACKERS] OUTER joins
Дата
Msg-id 199902241027.FAA09648@candle.pha.pa.us
обсуждение исходный текст
Ответ на OUTER joins  (Bruce Momjian <maillist@candle.pha.pa.us>)
Список pgsql-hackers
> 
> How do you propose doing outer joins in non-mergejoin situations?
> Mergejoins can only be used currently in equal joins.

Is your solution going to be to make sure the OUTER table is always a
MergeJoin, or on the outside of a join loop?  That could work.

That could get tricky if the table is joined to _two_ other tables. 
With the cleaned-up optimizer, we can disable non-merge joins in certain
circumstances, and prevent OUTER tables from being inner in the others. 
Is that the plan?

--  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: OUTER joins
Следующее
От: Oleg Broytmann
Дата:
Сообщение: Problem with complex query