Re: Possible to improve query plan?

От: Kevin Grittner
Тема: Re: Possible to improve query plan?
Дата: ,
Msg-id: 4D3DBE7B0200002500039B94@gw.wicourts.gov
(см: обсуждение, исходный текст)
Ответ на: Re: Possible to improve query plan?  (Jeremy Palmer)
Ответы: Re: Possible to improve query plan?  (Jeremy Palmer)
Список: pgsql-performance

Скрыть дерево обсуждения

Possible to improve query plan?  (Jeremy Palmer, )
   Re: Possible to improve query plan?  (Andy Colson, )
    Re: Possible to improve query plan?  (Jeremy Palmer, )
   Re: Possible to improve query plan?  ("Ing. Marcos Ortiz Valmaseda", )
    Re: Possible to improve query plan?  (Jeremy Palmer, )
   Re: Possible to improve query plan?  ("Kevin Grittner", )
    Re: Possible to improve query plan?  (Robert Haas, )
     Re: Possible to improve query plan?  ("Kevin Grittner", )
      Re: Possible to improve query plan?  (Tom Lane, )
       Re: Possible to improve query plan?  ("Kevin Grittner", )
        Re: Possible to improve query plan?  (Jeremy Palmer, )
         Re: Possible to improve query plan?  ("Kevin Grittner", )
          Re: Possible to improve query plan?  (Cédric Villemain, )
         Re: Possible to improve query plan?  ("Kevin Grittner", )
          Re: Possible to improve query plan?  (Jeremy Palmer, )
     Re: Possible to improve query plan?  (Tom Lane, )

Jeremy Palmer <> wrote:

> My only question is how often will I need to re-cluster the
> table, because it comes at quite a cost.

I probably should have mentioned that the CLUSTER will run faster if
the data is already mostly in the right sequence.  You'll be doing a
nearly sequential pass over the heap, which should minimize seek
time, especially if the OS notices the pattern and starts doing
sequential read-ahead.

-Kevin


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