From: Michael Stone
Subject: Re: SCSI vs SATA
Date: ,
Msg-id: 20070406132345.GE4374@mathom.us
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In response to: Re: SCSI vs SATA  (Ron)
Responses: Re: SCSI vs SATA  (Ron)
List: pgsql-performance

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SCSI vs SATA  ("", )
 Re: SCSI vs SATA  (Ron, )
  Re: SCSI vs SATA  (Ron, )
   Re: SCSI vs SATA  (Geoff Tolley, )
    Re: SCSI vs SATA  (, )
     Re: SCSI vs SATA  ("Peter Kovacs", )
      Re: SCSI vs SATA  (Andreas Kostyrka, )
       Re: SCSI vs SATA  (Alvaro Herrera, )
        Re: SCSI vs SATA  ("Peter Kovacs", )
         Re: SCSI vs SATA  (Alvaro Herrera, )
          Re: SCSI vs SATA  (Andreas Kostyrka, )
         Re: SCSI vs SATA  (, )
       Re: SCSI vs SATA  (Rod Taylor, )
     Re: SCSI vs SATA  (Geoff Tolley, )
    Re: SCSI vs SATA  ("", )
     Re: SCSI vs SATA  ("Joshua D. Drake", )
      Re: SCSI vs SATA  (Stefan Kaltenbrunner, )
       Re: SCSI vs SATA  ("Joshua D. Drake", )
        Re: SCSI vs SATA  (Stefan Kaltenbrunner, )
         Can't drop tablespace or user after disk gone  ("Craig A. James", )
          Re: Can't drop tablespace or user after disk gone  (Tom Lane, )
       Re: SCSI vs SATA  ("James Mansion", )
      Re: SCSI vs SATA  (Andreas Kostyrka, )
       Re: SCSI vs SATA  ("Joshua D. Drake", )
        Re: SCSI vs SATA  (, )
         Re: SCSI vs SATA  (Geoff Tolley, )
         Re: SCSI vs SATA  (Bruce Momjian, )
          Re: SCSI vs SATA  ("Joshua D. Drake", )
           Re: SCSI vs SATA  (Bruce Momjian, )
            Re: SCSI vs SATA  ("James Mansion", )
             Re: SCSI vs SATA  (Tom Lane, )
              Re: SCSI vs SATA  (Scott Marlowe, )
               Re: SCSI vs SATA  (Ron, )
                Re: SCSI vs SATA  (, )
                 Re: SCSI vs SATA  (Tom Lane, )
                  Re: SCSI vs SATA  (Greg Smith, )
                   Re: SCSI vs SATA  (Tom Lane, )
                    Re: SCSI vs SATA  (Geoffrey, )
                  Re: SCSI vs SATA  (Michael Stone, )
                   Re: SCSI vs SATA  (Geoffrey, )
               Re: SCSI vs SATA  ("James Mansion", )
                Re: SCSI vs SATA  (Scott Marlowe, )
                 Re: SCSI vs SATA  (, )
                  Re: SCSI vs SATA  (Ron, )
                   Re: SCSI vs SATA  (, )
                    Re: SCSI vs SATA  (Richard Troy, )
                    Re: SCSI vs SATA  (Ron, )
                     Re: SCSI vs SATA  (, )
                      Re: SCSI vs SATA  (Ron, )
                       Re: SCSI vs SATA  (Mark Kirkwood, )
                   Re: SCSI vs SATA  (Michael Stone, )
                    Re: SCSI vs SATA  (Ron, )
                     Re: SCSI vs SATA  (Michael Stone, )
                      Re: SCSI vs SATA  (Ron, )
                       Re: SCSI vs SATA  (Michael Stone, )
                        Re: SCSI vs SATA  (Ron, )
                         Re: SCSI vs SATA  (Michael Stone, )
                 Re: SCSI vs SATA  (Greg Smith, )
                  Re: SCSI vs SATA  (Scott Marlowe, )
                   Re: SCSI vs SATA  (Greg Smith, )
                   Re: SCSI vs SATA  (, )
                    Re: SCSI vs SATA  (Charles Sprickman, )
                     Re: SCSI vs SATA  (, )
                     Re: SCSI vs SATA  (Andreas Kostyrka, )
                   Re: SCSI vs SATA  (Bruce Momjian, )
                    Re: SCSI vs SATA  (Ron, )
                     Re: SCSI vs SATA  (, )
                      Re: SCSI vs SATA  (Ron, )
                       Re: SCSI vs SATA  (, )
                        Re: SCSI vs SATA  ("Joshua D. Drake", )
                        Re: SCSI vs SATA  (Ron, )
                       Re: SCSI vs SATA  (, )
                 Re: SCSI vs SATA  ("James Mansion", )
           Re: SCSI vs SATA  (Carlos Moreno, )
            Re: SCSI vs SATA  ("", )
             Re: SCSI vs SATA  (Arjen van der Meijden, )
             Re: SCSI vs SATA  (Heikki Linnakangas, )
             Re: SCSI vs SATA  (Ron, )
              Re: SCSI vs SATA  ("", )
               Re: SCSI vs SATA  ("Joshua D. Drake", )
               Re: SCSI vs SATA  ("Alex Deucher", )
               Re: SCSI vs SATA  (Arjen van der Meijden, )
               Re: SCSI vs SATA  (, )
     Re: SCSI vs SATA  (Geoff Tolley, )
     Re: SCSI vs SATA  (Scott Marlowe, )
      Re: SCSI vs SATA  (Jeff Frost, )
       Re: SCSI vs SATA  ("", )
 Re: SCSI vs SATA  ("Brian A. Seklecki", )
 Re: SCSI vs SATA  (Ron Mayer, )
 Re: SCSI vs SATA  (Ron, )
 Re: SCSI vs SATA  (Arjen van der Meijden, )
  Re: SCSI vs SATA  ("", )
   Re: SCSI vs SATA  (Arjen van der Meijden, )

On Fri, Apr 06, 2007 at 08:49:08AM -0400, Ron wrote:
>Not quite.  Each of our professional experiences is +also+
>statistical evidence.  Even if it is a personally skewed sample.

I'm not sure that word means what you think it means. I think the one
you're looking for is "anecdotal".

>My experience supports the hypothesis that spending slightly more for
>quality and treating HDs better is worth it.
>Does that mean one of us is right and the other wrong?  Nope.  Just
>that =in my experience= it does make a difference.

Well, without real numbers to back it up, it doesn't mean much in the
face of studies that include real numbers. Humans are, in general,
exceptionally lousy at assessing probabilities. There's a very real
tendency to exaggerate evidence that supports our preconceptions and
discount evidence that contradicts them. Maybe you're immune to that.
Personally, I tend to simply assume that anecdotal evidence isn't very
useful. This is why having some large scale independent studies is
valuable. The manufacturer's studies are obviously biased, and it's good
to have some basis for decision making other than "logic" (the classic
"proof by 'it stands to reason'"), marketing, or "I paid more for it" ("so
it's better whether it's better or not").

Mike Stone


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From: Tom Lane
Date:
Subject: Re: Premature view materialization in 8.2?
From: Ron
Date:
Subject: Re: SCSI vs SATA