От: Tom Lane
Тема: Re: Sort and index
Дата: ,
Msg-id: 19631.1113966086@sss.pgh.pa.us
(см: обсуждение, исходный текст)
Ответ на: Re: Sort and index  ("Jim C. Nasby")
Ответы: Re: Sort and index  ("Jim C. Nasby")
Список: pgsql-performance

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Sort and index  (Andrei Gaspar, )
 Re: Sort and index  ("Dave Held", )
  Re: Sort and index  (Andrei Gaspar, )
  Re: Sort and index  (Michael Fuhr, )
   Re: Sort and index  (Andrei Gaspar, )
  Re: Sort and index  ("Jim C. Nasby", )
   Re: Sort and index  (Tom Lane, )
    Re: Sort and index  ("Jim C. Nasby", )
     Re: Sort and index  ("Jim C. Nasby", )
      Re: Sort and index  (Tom Lane, )
       Re: Sort and index  ("Jim C. Nasby", )
        Re: Sort and index  (Tom Lane, )
         Re: Sort and index  ("Jim C. Nasby", )
          Re: Sort and index  (Manfred Koizar, )
           Re: Sort and index  ("Jim C. Nasby", )
            Re: Sort and index  (Manfred Koizar, )
             Re: Sort and index  ("Jim C. Nasby", )

"Jim C. Nasby" <> writes:
> Actually, the planner (at least in 7.4) isn't smart enough to consider
> if the sort would fit in memory or not.

Really?  Have you read cost_sort()?

It's certainly possible that the calculation is all wet, but to claim
that the issue is not considered is just wrong.

            regards, tom lane


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