Date: Sat, 18 Apr 2020 15:41:05 -0500
From: Justin Pryzby <pryzby@telsasoft.com>
To: Julien Rouhaud <rjuju123@gmail.com>
Cc: Amit Kapila <amit.kapila16@gmail.com>,
	Peter Eisentraut <peter.eisentraut@2ndquadrant.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>,
	PostgreSQL Hackers <pgsql-hackers@postgresql.org>,
	Thomas Munro <thomas.munro@gmail.com>
Subject: Re: WAL usage calculation patch
Message-ID: <20200418204105.GL26953@telsasoft.com>
References: 
 <CAA4eK1KqiWqAgw9ETchcQf-z9ZY4aUN-4QvTh0R26+DpNnTDHg@mail.gmail.com>
 <ef8c966f-e50a-c583-7b1e-85de6f4ca0d3@2ndquadrant.com>
 <20200406163109.GD2228@telsasoft.com>
 <CAA4eK1+Gwy=-teh7dGYY03qsYVAekHfokie8LWSwGXOGp3YOMw@mail.gmail.com>
 <61b66de7-ebb3-fada-b6d3-243386976631@2ndquadrant.com>
 <CAA4eK1Kj+m3Jtp0aT-P3V78StZomtV1w4Q2SPXydDQ9=1r5Nyg@mail.gmail.com>
 <CAA4eK1KTBtmbbkAHnFOKs2Jt2ArF0T83OG=NnNFmdjQ4k-SLQA@mail.gmail.com>
 <96013912-6742-be14-dca4-6e8394cc0541@2ndquadrant.com>
 <CAA4eK1KzxnD_+ubx41+CytQExbFCBH6ar5NLVcNO6Lh1oo+Hyw@mail.gmail.com>
 <CAOBaU_ZbVMGta+1OkTn3qsPd=myi9cgv1hQFpdrQZdhDOjq8PA@mail.gmail.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: 
 <CAOBaU_ZbVMGta+1OkTn3qsPd=myi9cgv1hQFpdrQZdhDOjq8PA@mail.gmail.com>
User-Agent: Mutt/1.9.4 (2018-02-28)
Precedence: bulk

On Sat, Apr 18, 2020 at 05:39:35PM +0200, Julien Rouhaud wrote:
> On Sat, Apr 18, 2020 at 6:16 AM Amit Kapila <amit.kapila16@gmail.com> wrote:
> >
> > On Fri, Apr 17, 2020 at 6:45 PM Peter Eisentraut <peter.eisentraut@2ndquadrant.com> wrote:
> > > On 2020-04-14 05:57, Amit Kapila wrote:
> > > > Peter E, others, any suggestions on how to move forward?  I think here
> > > > we should follow the rule "follow the style of nearby code" which in
> > > > this case would be to have one space after each field as we would like
> > > > it to be closer to the "Buffers" format.  It would be good if we have
> > > > a unified format among all Explain stuff but we might not want to
> > > > change the existing things and even if we want to do that it might be
> > > > a broader/bigger change and we should do that as a PG14 change.  What
> > > > do you think?
> > >
> > > If looks like shortening to fpw= and using one space is the easiest way
> > > to solve this issue.
> > >
> >
> > I am fine with this approach and will change accordingly.  I will wait
> > for a few days (3-4 days) to see if someone shows up with either an
> > objection to this or with a better idea for the display of WAL usage
> > information.
> 
> That was also my preferred alternative.  PFA a patch for that.  I also
> changed to "fpw" for the non textual output for consistency.

Should capitalize at least the non-text one ?  And maybe the text one for
consistency ?

+               ExplainPropertyInteger("WAL fpw", NULL,                                                                                                                                              

And add the acronym to the docs:

$ git grep 'full page' '*/explain.sgml'
doc/src/sgml/ref/explain.sgml:      number of records, number of full page writes and amount of WAL bytes

"..full page writes (FPW).."

Should we also change vacuumlazy.c for consistency ?

+                                                        _("WAL usage: %ld records, %ld full page writes, "
+                                                          UINT64_FORMAT " bytes"),

-- 
Justin