Horton

Re: WAL usage calculation patch

Julien Rouhaud <rjuju123@gmail.com>

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From: Julien Rouhaud <rjuju123@gmail.com>
To: Amit Kapila <amit.kapila16@gmail.com>
Cc: Euler Taveira <euler.taveira@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>
Date: 2020-04-13T07:40:14Z
Lists: pgsql-hackers

Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →

  1. Change the display of WAL usage statistics in Explain.

  2. Cosmetic fixups for WAL usage work.

  3. Allow parallel create index to accumulate buffer usage stats.

  4. Allow autovacuum to log WAL usage statistics.

  5. Add the option to report WAL usage in EXPLAIN and auto_explain.

  6. Allow pg_stat_statements to track WAL usage statistics.

  7. Add infrastructure to track WAL usage.

  8. Include information on buffer usage during planning phase, in EXPLAIN output, take two.

  9. Include information on buffer usage during planning phase, in EXPLAIN output.

  10. Allow parallel vacuum to accumulate buffer usage.

  11. Allow pg_stat_statements to track planning statistics.

On Mon, Apr 13, 2020 at 8:11 AM Amit Kapila <amit.kapila16@gmail.com> wrote:
>
> On Sat, Apr 11, 2020 at 6:55 PM Julien Rouhaud <rjuju123@gmail.com> wrote:
> >
> > On Fri, Apr 10, 2020 at 9:37 PM Julien Rouhaud <rjuju123@gmail.com> wrote:
> > >
> > I tried to take into account all that have been discussed, but I have
> > to admit that I'm absolutely not sure of what was actually decided
> > here.  I went with those changes:
> >
> > - rename wal_num_fpw to wal_fpw for consistency, both in pgss view
> > fiel name but also everywhere in the code
> > - change comments to consistently mention "full page writes generated"
> > - changed pgss and explain documentation to mention "full page images
> > generated", from Justin's patch on another thread
> >
>
> I think it is better to use "full page writes" to be consistent with
> other places.
>
> > - kept "amount" of WAL bytes
> >
>
> Okay, but I would like to make another change suggested by Justin
> which is to replace "count" with "number" at a few places.

Ah sorry I missed this one.  +1 it also sounds better.

> I have made the above two changes in the attached.  Let me know what
> you think about attached?

It all looks good to me!

> > - no change to the explain output as I have no idea what is the
> > consensus (one or two spaces, use semicolon or equal, show unit or
> > not)
> >
>
> Yeah, let's do this separately once we have consensus.

Agreed.