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Date: Thu, 20 May 2021 19:54:37 -0400
From: Bruce Momjian <bruce@momjian.us>
To: Peter Geoghegan <pg@bowt.ie>
Cc: Alvaro Herrera <alvherre@alvh.no-ip.org>,
	Justin Pryzby <pryzby@telsasoft.com>,
	PostgreSQL Hackers <pgsql-hackers@postgresql.org>
Subject: Re: PG 14 release notes, first draft
Message-ID: <20210520235437.GG8971@momjian.us>
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On Thu, May 20, 2021 at 04:19:50PM -0700, Peter Geoghegan wrote:
> On Thu, May 20, 2021 at 2:37 PM Bruce Momjian <bruce@momjian.us> wrote:
> > I went with this text:
> >
> >         Reduce the default value of <varname><xref
> >         linkend="guc-vacuum-cost-page-miss"></varname> from 10 milliseconds to 2
> >         (Peter Geoghegan)
> >
> > I think with numbers, and the fact we are saying "decrease" havint them
> > in the from/to order is best.  If this was non-numeric, like to scram
> > from md5, it would make more sense to use to/from.
> 
> The point of this change was to make the cost of dirtying pages much
> higher than everything else, since writes are in effect much more
> expensive on modern hardware. Don't know if you need to say that.

I think our text "This new default better reflects current hardware
capabilities." is detailed enough.  People can dig into the item to see
what it does and how it adjusts costs.

-- 
  Bruce Momjian  <bruce@momjian.us>        https://momjian.us
  EDB                                      https://enterprisedb.com

  If only the physical world exists, free will is an illusion.