Re: WAL usage calculation patch

At Sun, 19 Apr 2020 16:22:26 +0200, Julien Rouhaud <rjuju123@gmail.com> wrote in 
> Hi Justin,
> 
> Thanks for the review!
> 
> On Sat, Apr 18, 2020 at 10:41 PM Justin Pryzby <pryzby@telsasoft.com> wrote:
> >
> > Should capitalize at least the non-text one ?  And maybe the text one for
> > consistency ?
> >
> > +               ExplainPropertyInteger("WAL fpw", NULL,
> 
> I think we should keep both version consistent, whether lower or upper
> case.  The uppercase version is probably more correct, but it's a
> little bit weird to have it being the only upper case label in all
> output, so I kept it lower case.

One space follwed by an acronym looks perfect.  I'd prefer capital
letters but small-letters also works well.

> > 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).."
> 
> Indeed!  Fixed (using lowercase to match current output).

I searched through the documentation and AFAICS most of occurances of
"full page" are follwed by "image" and full_page_writes is used only
as the parameter name.

I'm fine with fpw as the acronym, but "fpw means the number of full
page images" looks odd..

> > Should we also change vacuumlazy.c for consistency ?
> >
> > +                                                        _("WAL usage: %ld records, %ld full page writes, "
> > +                                                          UINT64_FORMAT " bytes"),
> 
> I don't think this one should be changed, vacuumlazy output is already
> entirely different, and is way more verbose so keeping it as is makes
> sense to me.

regards.

-- 
Kyotaro Horiguchi
NTT Open Source Software Center