Re: Throwing unnecessary joins away

От: Tom Lane
Тема: Re: Throwing unnecessary joins away
Дата: ,
Msg-id: 5269.1137081233@sss.pgh.pa.us
(см: обсуждение, исходный текст)
Ответ на: Re: Throwing unnecessary joins away  (Ottó Havasvölgyi)
Ответы: Re: Throwing unnecessary joins away  (Szűcs Gábor)
Re: Throwing unnecessary joins away  (Ottó Havasvölgyi)
Список: pgsql-performance

Скрыть дерево обсуждения

Throwing unnecessary joins away  (Ottó Havasvölgyi, )
 Re: Throwing unnecessary joins away  (Alessandro Baretta, )
  Re: Throwing unnecessary joins away  (Ottó Havasvölgyi, )
   Re: Throwing unnecessary joins away  (Tom Lane, )
    Re: Throwing unnecessary joins away  (Szűcs Gábor, )
    Re: Throwing unnecessary joins away  (Ottó Havasvölgyi, )
     Re: Throwing unnecessary joins away  (Scott Marlowe, )
      Re: Throwing unnecessary joins away  (Ottó Havasvölgyi, )
       Re: Throwing unnecessary joins away  ("Jim C. Nasby", )
  Re: Throwing unnecessary joins away  ("Jim C. Nasby", )

=?ISO-8859-1?Q?Ott=F3_Havasv=F6lgyi?= <> writes:
> As far as I know SQL Server has some similar feature. It does not join
> if not necessary, more exactly: if the result would be the same if it
> joined the table.

I find it really really hard to believe that such cases arise often
enough to justify having the planner spend cycles checking for them.

            regards, tom lane


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