Re: WAL usage calculation patch

Julien Rouhaud <rjuju123@gmail.com>

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: 2020-04-11T13:24:47Z

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 →

Change the display of WAL usage statistics in Explain.
- 69bfaf2e1de4 13.0 landed
Cosmetic fixups for WAL usage work.
- ef08ca113fe3 13.0 landed
Allow parallel create index to accumulate buffer usage stats.
- 5c71362174eb 13.0 landed
- f179e9f01b65 11.8 landed
- 13823ad3b012 12.3 landed
Allow autovacuum to log WAL usage statistics.
- b7ce6de93b59 13.0 landed
Add the option to report WAL usage in EXPLAIN and auto_explain.
- 33e05f89c53e 13.0 landed
Allow pg_stat_statements to track WAL usage statistics.
- 6b466bf5f2be 13.0 landed
Add infrastructure to track WAL usage.
- df3b181499b4 13.0 landed
Include information on buffer usage during planning phase, in EXPLAIN output, take two.
- ce77abe63cfc 13.0 cited
Include information on buffer usage during planning phase, in EXPLAIN output.
- ed7a5095716e 13.0 cited
Allow parallel vacuum to accumulate buffer usage.
- 3a5e22138a8d 13.0 landed
Allow pg_stat_statements to track planning statistics.
- 17e03282241c 13.0 cited

Attachments

v1-wal_usage_fixup.diff (text/x-patch) patch v1

On Fri, Apr 10, 2020 at 9:37 PM Julien Rouhaud <rjuju123@gmail.com> wrote:
>
> On Fri, Apr 10, 2020 at 8:17 AM Amit Kapila <amit.kapila16@gmail.com> wrote:
> > Would you like to send a consolidated patch that includes Euler's
> > suggestion and Justin's patch (by making changes for points we
> > discussed.)?  I think we can keep the point related to number of
> > spaces before each field open?
>
> Sure, I'll take care of that tomorrow!

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
- kept "amount" of WAL bytes
- 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)