Re: performance with query

От: Tom Lane
Тема: Re: performance with query
Дата: ,
Msg-id: 15480.1245166290@sss.pgh.pa.us
(см: обсуждение, исходный текст)
Ответ на: Re: performance with query  (Alberto Dalmaso)
Ответы: Re: performance with query  (Alberto Dalmaso)
Список: pgsql-performance

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performance with query  (Alberto Dalmaso, )
 Re: performance with query  (Joshua Tolley, )
 Re: performance with query  ("Kevin Grittner", )
 Re: performance with query  (Alberto Dalmaso, )
  Re: performance with query  (Matthew Wakeling, )
   Re: performance with query  (Alberto Dalmaso, )
    Re: performance with query  (Tom Lane, )
     Re: performance with query  (Alberto Dalmaso, )
      Re: performance with query  (Tom Lane, )
      Re: performance with query (OT)  ("Albe Laurenz", )
    Re: performance with query  ("Kevin Grittner", )
  Re: performance with query  ("Kevin Grittner", )
   Re: performance with query  (Alberto Dalmaso, )
    Re: performance with query  ("Kevin Grittner", )
    Re: performance with query  ("Kevin Grittner", )
     Re: performance with query  (Alberto Dalmaso, )
      Speeding up a query.  ("Hartman, Matthew", )
       Re: Speeding up a query.  (Anthony Presley, )
        Re: Speeding up a query.  ("Hartman, Matthew", )
       Re: Speeding up a query.  ("Albe Laurenz", )
        Re: Speeding up a query.  (Grzegorz Jaśkiewicz, )
       Re: Speeding up a query.  (Alberto Dalmaso, )
        Re: Speeding up a query.  ("Kevin Grittner", )
        Re: Speeding up a query.  (Tom Lane, )
       Re: Speeding up a query.  (Merlin Moncure, )
        Re: Speeding up a query.  ("Hartman, Matthew", )
       Re: Speeding up a query.  ("Hartman, Matthew", )
       Re: Speeding up a query.  (Simon Riggs, )
        Re: Speeding up a query.  ("Hartman, Matthew", )
 Re: performance with query  (Alberto Dalmaso, )
 Re: performance with query  (Alberto Dalmaso, )
  Re: performance with query  ("Kevin Grittner", )
   Re: performance with query  (Alberto Dalmaso, )
    Re: performance with query  ("Kevin Grittner", )
     Re: performance with query  (Alberto Dalmaso, )
      Re: performance with query  ("Kevin Grittner", )
       Re: performance with query  (Tom Lane, )
        Re: performance with query  ("Kevin Grittner", )

Alberto Dalmaso <> writes:
> Il giorno mar, 16/06/2009 alle 15.58 +0100, Matthew Wakeling ha scritto:
>>> enable_hashjoin = off
>>> enable_nestloop = off
>>> enable_seqscan = off
>>> enable_sort = off
>>
>> Why are these switched off?
>>
> because of the need to pump up the performance of the complex query.

That is *not* the way to improve performance of a query.  Turning off
specific enable_ parameters can be helpful while investigating planner
behavior, but it is never recommended as a production solution.  You
have already found out why.

            regards, tom lane


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