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From: Peter Geoghegan <[email protected]>
To: Tom Lane <[email protected]>
Cc: Felix Geisendörfer <[email protected]>
Cc: postgres performance list <[email protected]>
Subject: Re: 10x faster sort performance on Skylake CPU vs Ivy Bridge
Date: Fri, 25 Aug 2017 08:43:49 -0700
Message-ID: <CAH2-WznaO1jsm1MsnpwAp4PArxP9NDhV-zHMgTy8sG6_OMwN7A@mail.gmail.com> (raw)
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On Fri, Aug 25, 2017 at 8:07 AM, Tom Lane <[email protected]> wrote:
> I doubt this is a hardware issue, it's more likely that you're comparing
> apples and oranges.  The first theory that springs to mind is that the
> sort keys are strings and you're using C locale on the faster machine but
> some non-C locale on the slower.  strcoll() is pretty darn expensive
> compared to strcmp() :-(

strcoll() is very noticeably slower on macOS, too.

-- 
Peter Geoghegan


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