Re: WAL usage calculation patch

On Fri, Apr 3, 2020 at 6:37 AM Amit Kapila <amit(dot)kapila16(at)gmail(dot)com> wrote:
>
> On Thu, Apr 2, 2020 at 8:06 PM Dilip Kumar <dilipbalaut(at)gmail(dot)com> wrote:
> >
> > On Thu, Apr 2, 2020 at 6:41 PM Amit Kapila <amit(dot)kapila16(at)gmail(dot)com> wrote:
> > >
> > > 4.
> > > /* # of WAL full page image generated */
> > > Can we change it to "/* # of WAL full page image records generated */"?
> >
> > IMHO, "# of WAL full-page image records" seems like the number of wal
> > record which contains the full-page image.
> >
>
> I think this resembles what you have written here.
>
> > But, actually, this is the
> > total number of the full-page images, not the number of records that
> > have a full-page image.
> >
>
> We count this when forming WAL records. As per my understanding, all
> three counters are about WAL records. This counter tells how many
> records have full page images and one of the purposes of having this
> counter is to check what percentage of records contain full page
> image.
>

How about if say "# of full-page writes generated" or "# of WAL
full-page writes generated"? I think now I understand your concern
because we want to display it as full page writes and the comment
doesn't seem to indicate the same.

With Regards,
Amit Kapila.
EnterpriseDB: http://www.enterprisedb.com