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Date: Thu, 23 Feb 2017 15:03:39 -0300
From: Alvaro Herrera <alvherre@2ndquadrant.com>
To: Bruce Momjian <bruce@momjian.us>
Cc: Pavan Deolasee <pavan.deolasee@gmail.com>,
	Jaime Casanova <jaime.casanova@2ndquadrant.com>,
	Haribabu Kommi <kommi.haribabu@gmail.com>,
	Tomas Vondra <tomas.vondra@2ndquadrant.com>,
	pgsql-hackers <pgsql-hackers@postgresql.org>
Subject: Re: Patch: Write Amplification Reduction Method (WARM)
Message-ID: <20170223180339.sp6dkumsklt44kys@alvherre.pgsql>
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Bruce Momjian wrote:

> As I remember, WARM only allows
> a single index-column change in the chain.  Why are you seeing such a
> large performance improvement?  I would have thought it would be that
> high if we allowed an unlimited number of index changes in the chain.

The second update in a chain creates another non-warm-updated tuple, so
the third update can be a warm update again, and so on.

-- 
Álvaro Herrera                https://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services


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