Re: 8.4 Performance improvements: was Re: Proposal of tunable fix for scalability of 8.4

From: Tom Lane
Subject: Re: 8.4 Performance improvements: was Re: Proposal of tunable fix for scalability of 8.4
Date: ,
Msg-id: 4861.1237045925@sss.pgh.pa.us
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In response to: Re: 8.4 Performance improvements: was Re: Proposal of tunable fix for scalability of 8.4  (Robert Haas)
List: pgsql-performance

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Proposal of tunable fix for scalability of 8.4  ("Jignesh K. Shah", )
 Re: Proposal of tunable fix for scalability of 8.4  ("Kevin Grittner", )
  Re: Proposal of tunable fix for scalability of 8.4  ("Jignesh K. Shah", )
   Re: Proposal of tunable fix for scalability of 8.4  ("Kevin Grittner", )
  Re: Proposal of tunable fix for scalability of 8.4  (Tom Lane, )
   Re: Proposal of tunable fix for scalability of 8.4  ("Jignesh K. Shah", )
    Re: Proposal of tunable fix for scalability of 8.4  (Simon Riggs, )
     Re: Proposal of tunable fix for scalability of 8.4  ("Jignesh K. Shah", )
     Re: Proposal of tunable fix for scalability of 8.4  ("Jignesh K. Shah", )
      Re: Proposal of tunable fix for scalability of 8.4  (Simon Riggs, )
       Re: Proposal of tunable fix for scalability of 8.4  ("Jignesh K. Shah", )
        Re: Proposal of tunable fix for scalability of 8.4  (Simon Riggs, )
        Re: Proposal of tunable fix for scalability of 8.4  (Gregory Stark, )
         Re: Proposal of tunable fix for scalability of 8.4  (Scott Carey, )
          Re: Proposal of tunable fix for scalability of 8.4  ("Jignesh K. Shah", )
  Re: Proposal of tunable fix for scalability of 8.4  (Scott Carey, )
   Re: Proposal of tunable fix for scalability of 8.4  (Tom Lane, )
    Re: Proposal of tunable fix for scalability of 8.4  ("Jignesh K. Shah", )
     Re: Proposal of tunable fix for scalability of 8.4  (decibel, )
      Re: Proposal of tunable fix for scalability of 8.4  ("Jignesh K. Shah", )
       Re: Proposal of tunable fix for scalability of 8.4  (Josh Berkus, )
    Re: Proposal of tunable fix for scalability of 8.4  (Scott Carey, )
     Re: Proposal of tunable fix for scalability of 8.4  ("Jignesh K. Shah", )
      Re: Proposal of tunable fix for scalability of 8.4  ("Kevin Grittner", )
      Re: Proposal of tunable fix for scalability of 8.4  (Scott Carey, )
       Re: Proposal of tunable fix for scalability of 8.4  ("Jignesh K. Shah", )
        Re: Proposal of tunable fix for scalability of 8.4  (Gregory Stark, )
         Re: Proposal of tunable fix for scalability of 8.4  ("Jignesh K. Shah", )
          Re: Proposal of tunable fix for scalability of 8.4  (Gregory Stark, )
         Re: Proposal of tunable fix for scalability of 8.4  (decibel, )
        Re: Proposal of tunable fix for scalability of 8.4  (Gregory Stark, )
        Re: Proposal of tunable fix for scalability of 8.4  ("Jignesh K. Shah", )
         Re: Proposal of tunable fix for scalability of 8.4  ("Kevin Grittner", )
          Re: Proposal of tunable fix for scalability of 8.4  (Scott Carey, )
           Re: Proposal of tunable fix for scalability of 8.4  ("Jignesh K. Shah", )
         Re: Proposal of tunable fix for scalability of 8.4  ("Kevin Grittner", )
         Re: Proposal of tunable fix for scalability of 8.4  ("Jignesh K. Shah", )
          Re: Proposal of tunable fix for scalability of 8.4  (Scott Carey, )
           Re: Proposal of tunable fix for scalability of 8.4  (Scott Carey, )
            Re: Proposal of tunable fix for scalability of 8.4  ("Jignesh K. Shah", )
          Re: Proposal of tunable fix for scalability of 8.4  ("Jignesh K. Shah", )
           Re: Proposal of tunable fix for scalability of 8.4  (decibel, )
            Re: Proposal of tunable fix for scalability of 8.4  ("Jignesh K. Shah", )
             Re: Proposal of tunable fix for scalability of 8.4  (Gregory Stark, )
              Re: Proposal of tunable fix for scalability of 8.4  ("Jignesh K. Shah", )
      Re: Proposal of tunable fix for scalability of 8.4  (Greg Smith, )
   Re: Proposal of tunable fix for scalability of 8.4  ("Jignesh K. Shah", )
    Re: Proposal of tunable fix for scalability of 8.4  (Scott Carey, )
    Re: Proposal of tunable fix for scalability of 8.4  (Greg Smith, )
     Re: Proposal of tunable fix for scalability of 8.4  (Scott Carey, )
      Re: Proposal of tunable fix for scalability of 8.4  (Robert Haas, )
       Re: Proposal of tunable fix for scalability of 8.4  (Tom Lane, )
        Re: Proposal of tunable fix for scalability of 8.4  (Scott Carey, )
        Re: Proposal of tunable fix for scalability of 8.4  ("Kevin Grittner", )
         Re: Proposal of tunable fix for scalability of 8.4  (Scott Carey, )
         Re: Proposal of tunable fix for scalability of 8.4  (, )
          Re: Proposal of tunable fix for scalability of 8.4  ("Kevin Grittner", )
           Re: Proposal of tunable fix for scalability of 8.4  ("Kevin Grittner", )
            Re: Proposal of tunable fix for scalability of 8.4  (Scott Carey, )
        Re: Proposal of tunable fix for scalability of 8.4  (Heikki Linnakangas, )
         Re: Proposal of tunable fix for scalability of 8.4  (Tom Lane, )
          Re: Proposal of tunable fix for scalability of 8.4  (Scott Carey, )
          Re: Proposal of tunable fix for scalability of 8.4  (Simon Riggs, )
         Re: Proposal of tunable fix for scalability of 8.4  (Matthew Wakeling, )
          Re: Proposal of tunable fix for scalability of 8.4  (Simon Riggs, )
           Re: Proposal of tunable fix for scalability of 8.4  (Matthew Wakeling, )
            Re: Proposal of tunable fix for scalability of 8.4  (Simon Riggs, )
             Re: Proposal of tunable fix for scalability of 8.4  (Matthew Wakeling, )
             Re: Proposal of tunable fix for scalability of 8.4  ("Jignesh K. Shah", )
              Re: Proposal of tunable fix for scalability of 8.4  (Matthew Wakeling, )
               Re: Proposal of tunable fix for scalability of 8.4  (Simon Riggs, )
           Re: Proposal of tunable fix for scalability of 8.4  (Tom Lane, )
            Re: Proposal of tunable fix for scalability of 8.4  (Simon Riggs, )
           Re: Proposal of tunable fix for scalability of 8.4  (Scott Carey, )
            Re: Proposal of tunable fix for scalability of 8.4  (Matthew Wakeling, )
             Re: Proposal of tunable fix for scalability of 8.4  (Tom Lane, )
             Re: Proposal of tunable fix for scalability of 8.4  (Scott Carey, )
             Re: Proposal of tunable fix for scalability of 8.4  (Simon Riggs, )
          Re: Proposal of tunable fix for scalability of 8.4  (Heikki Linnakangas, )
           Re: Proposal of tunable fix for scalability of 8.4  (Matthew Wakeling, )
       Re: Proposal of tunable fix for scalability of 8.4  (Scott Carey, )
        Re: Proposal of tunable fix for scalability of 8.4  (Robert Haas, )
         Re: Proposal of tunable fix for scalability of 8.4  ("Jignesh K. Shah", )
          Re: Proposal of tunable fix for scalability of 8.4  (Robert Haas, )
           Re: Proposal of tunable fix for scalability of 8.4  (Scott Carey, )
            Re: Proposal of tunable fix for scalability of 8.4  (Robert Haas, )
             Re: Proposal of tunable fix for scalability of 8.4  (Scott Carey, )
              Re: Proposal of tunable fix for scalability of 8.4  (Alvaro Herrera, )
               Re: Proposal of tunable fix for scalability of 8.4  (Alvaro Herrera, )
                Re: Proposal of tunable fix for scalability of 8.4  (Alvaro Herrera, )
                 Re: Proposal of tunable fix for scalability of 8.4  ("Jignesh K. Shah", )
                  Re: Proposal of tunable fix for scalability of 8.4  (Robert Haas, )
                   Re: Proposal of tunable fix for scalability of 8.4  ("Jignesh K. Shah", )
           Re: Proposal of tunable fix for scalability of 8.4  ("Jignesh K. Shah", )
         Re: Proposal of tunable fix for scalability of 8.4  (Bruce Momjian, )
          Re: Proposal of tunable fix for scalability of 8.4  (Scott Carey, )
           Re: Proposal of tunable fix for scalability of 8.4  (Bruce Momjian, )
         Re: Proposal of tunable fix for scalability of 8.4  (Scott Carey, )
      Re: Proposal of tunable fix for scalability of 8.4  (Greg Smith, )
     8.4 Performance improvements: was Re: Proposal of tunable fix for scalability of 8.4  ("Jignesh K. Shah", )
      Re: 8.4 Performance improvements: was Re: Proposal of tunable fix for scalability of 8.4  (Gregory Stark, )
      Re: 8.4 Performance improvements: was Re: Proposal of tunable fix for scalability of 8.4  (Gregory Stark, )
       Re: 8.4 Performance improvements: was Re: Proposal of tunable fix for scalability of 8.4  (Alan Stange, )
        Re: 8.4 Performance improvements: was Re: Proposal of tunable fix for scalability of 8.4  (Tom Lane, )
         Re: 8.4 Performance improvements: was Re: Proposal of tunable fix for scalability of 8.4  (Gregory Stark, )
          Re: 8.4 Performance improvements: was Re: Proposal of tunable fix for scalability of 8.4  (Tom Lane, )
           Re: 8.4 Performance improvements: was Re: Proposal of tunable fix for scalability of 8.4  (Robert Haas, )
            Re: 8.4 Performance improvements: was Re: Proposal of tunable fix for scalability of 8.4  (Gregory Stark, )
            Re: 8.4 Performance improvements: was Re: Proposal of tunable fix for scalability of 8.4  (Tom Lane, )
           Re: 8.4 Performance improvements: was Re: Proposal of tunable fix for scalability of 8.4  (Bruce Momjian, )
            Re: 8.4 Performance improvements: was Re: Proposal of tunable fix for scalability of 8.4  (Bruce Momjian, )
      Re: 8.4 Performance improvements: was Re: Proposal of tunable fix for scalability of 8.4  (Greg Smith, )
   Re: Proposal of tunable fix for scalability of 8.4  ("Kevin Grittner", )
    Re: Proposal of tunable fix for scalability of 8.4  (Grzegorz Jaśkiewicz, )
     Re: Proposal of tunable fix for scalability of 8.4  ("Kevin Grittner", )
      Re: Proposal of tunable fix for scalability of 8.4  (Ron, )
     Re: Proposal of tunable fix for scalability of 8.4  (Gregory Stark, )
      Re: Proposal of tunable fix for scalability of 8.4  (Scott Carey, )
    Re: Proposal of tunable fix for scalability of 8.4  (Scott Carey, )
     Re: Proposal of tunable fix for scalability of 8.4  (Tom Lane, )
      Re: Proposal of tunable fix for scalability of 8.4  (Alvaro Herrera, )
       Re: Proposal of tunable fix for scalability of 8.4  ("Jignesh K. Shah", )
        Re: Proposal of tunable fix for scalability of 8.4  (decibel, )
      Re: Proposal of tunable fix for scalability of 8.4  (Scott Carey, )
    Re: Proposal of tunable fix for scalability of 8.4  (Tom Lane, )
     Re: Proposal of tunable fix for scalability of 8.4  (Scott Carey, )
    Re: Proposal of tunable fix for scalability of 8.4  ("Jignesh K. Shah", )
 Re: Proposal of tunable fix for scalability of 8.4  (Simon Riggs, )
  Re: Proposal of tunable fix for scalability of 8.4  ("Jignesh K. Shah", )

Robert Haas <> writes:
> On Fri, Mar 13, 2009 at 10:06 PM, Tom Lane <> wrote:
>> I assume you meant effective_io_concurrency. �We'd still need a special
>> case because the default is currently hard-wired at 1, not 0, if
>> configure thinks the function exists.

> I think 1 should mean no prefetching, rather than 0.

No, 1 means "prefetch a single block ahead".  It doesn't involve I/O
concurrency in the sense of multiple I/O requests being processed at
once; what it does give you is CPU vs I/O concurrency.  0 shuts that
down and returns the system to pre-8.4 behavior.

            regards, tom lane


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From: decibel
Date:
Subject: Re: Proposal of tunable fix for scalability of 8.4
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Date:
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