From: Michael Stone <mstone+postgres@mathom.us>
To: pgsql-performance@postgresql.org
Subject: Re: SCSI vs SATA
Date: Fri, 06 Apr 2007 09:23:48 -0400
Message-ID: <20070406132345.GE4374@mathom.us> (raw)
In-Reply-To: <E1HZnsP-0006wx-OL@elasmtp-spurfowl.atl.sa.earthlink.net>
References: <HCEPKPMCAJLDGJIBCLGHEENIHGAA.james@mansionfamily.plus.com>
<1175807611.9839.120.camel@state.g2switchworks.com>
<Pine.LNX.4.64.0704051905520.28411@asgard.lang.hm>
<E1HZeyl-0000cI-NU@elasmtp-masked.atl.sa.earthlink.net>
<20070406113816.GC4374@mathom.us>
<E1HZnsP-0006wx-OL@elasmtp-spurfowl.atl.sa.earthlink.net>
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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To: pgsql-performance@postgresql.org
Cc: mstone+postgres@mathom.us
Subject: Re: SCSI vs SATA
In-Reply-To: <20070406132345.GE4374@mathom.us>
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