Re: Resetting spilled txn statistics in pg_stat_replication

On Thu, 22 Oct 2020 at 20:34, Amit Kapila <amit(dot)kapila16(at)gmail(dot)com> wrote:
>
> On Thu, Oct 22, 2020 at 4:09 PM Masahiko Sawada
> <masahiko(dot)sawada(at)2ndquadrant(dot)com> wrote:
> >
> > On Wed, 21 Oct 2020 at 12:56, Amit Kapila <amit(dot)kapila16(at)gmail(dot)com> wrote:
> > >
> > > On Tue, Oct 13, 2020 at 10:33 AM Amit Kapila <amit(dot)kapila16(at)gmail(dot)com> wrote:
> > > >
> > > > On Tue, Oct 13, 2020 at 10:21 AM Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
> > > > >
> > > > >
> > > > > I know I can go read the source code, but most users will not want to.
> > > > > Is the documentation in monitoring.sgml really sufficient? If we can't
> > > > > explain this with more precision, is it really a number we want to expose
> > > > > at all?
> > > > >
> > > >
> > > > This counter is important to give users an idea about the amount of
> > > > I/O we incur during decoding and to tune logical_decoding_work_mem
> > > > GUC. So, I would prefer to improve the documentation for this
> > > > variable.
> > > >
> > >
> > > I have modified the description of spill_count and spill_txns to make
> > > things clear. Any suggestions?
> >
> > Thank you for the patch.
> >
> > - logical decoding exceeds
> > <literal>logical_decoding_work_mem</literal>. The
> > - counter gets incremented both for toplevel transactions and
> > - subtransactions.
> > + logical decoding of changes from WAL for this exceeds
> > + <literal>logical_decoding_work_mem</literal>. The counter gets
> > + incremented both for toplevel transactions and subtransactions.
> >
> > What is the word "this" in the above change referring to?
> >
>
> 'slot'. The word *slot* is missing in the sentence.
>
> > How about
> > something like:
> >
>
> > Number of transactions spilled to disk after the memory used by
> > logical decoding of changes from WAL exceeding
> > logical_decoding_work_mem. The counter gets incremented both for
> > toplevel transactions and subtransactions.
> >
>
> /exceeding/exceeds. I am fine with your proposed text as well but if
> you like the above after correction that would be better because it
> would be more close to spill_count description.

yeah, I agree with the correction.

Regards,

--
Masahiko Sawada http://www.2ndQuadrant.com/
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