Subject: Re: WAL usage calculation patch
To: Julien Rouhaud <rjuju123@gmail.com>, Amit Kapila <amit.kapila16@gmail.com>
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Cc: Justin Pryzby <pryzby@telsasoft.com>,
 Kyotaro Horiguchi <horikyota.ntt@gmail.com>,
 Dilip Kumar <dilipbalaut@gmail.com>,
 Kuntal Ghosh <kuntalghosh.2007@gmail.com>,
 Fujii Masao <masao.fujii@oss.nttdata.com>,
 Kirill Bychik <kirill.bychik@gmail.com>,
 pgsql-hackers <pgsql-hackers@postgresql.org>,
 Thomas Munro <thomas.munro@gmail.com>
From: Peter Eisentraut <peter.eisentraut@2ndquadrant.com>
Organization: 2ndQuadrant
Message-ID: <05bdb944-e12b-232a-41c0-e78cc9e63d17@2ndquadrant.com>
Date: Thu, 23 Apr 2020 08:46:50 +0200
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On 2020-04-23 07:31, Julien Rouhaud wrote:
> I agree that full page writes can be used in this case, but I'm
> wondering if that can be misleading for some reader which might e.g.
> confuse with the full_page_writes GUC.  And as Justin pointed out, the
> documentation for now usually mentions "full page image(s)" in such
> cases.

ISTM that in the context of this patch, "full-page image" is correct.  A 
"full-page write" is what you do to a table or index page when you are 
recovering a full-page image.  The internal symbol for the WAL record is 
XLOG_FPI and xlogdesc.c prints it as "FPI".

-- 
Peter Eisentraut              http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services