Horton

Re: pgBufferUsage.blk_{read|write}_time are zero although there are pgBufferUsage.local_blks_{read|written}

hubert depesz lubaczewski <depesz@depesz.com>

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From: hubert depesz lubaczewski <depesz@depesz.com>
To: Michael Paquier <michael@paquier.xyz>
Cc: Nazir Bilal Yavuz <byavuz81@gmail.com>, Robert Haas <robertmhaas@gmail.com>, Melanie Plageman <melanieplageman@gmail.com>, pgsql-hackers <pgsql-hackers@postgresql.org>
Date: 2023-10-31T14:11:03Z
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. Fix description of I/O timing info for shared buffers in EXPLAIN (BUFFERS)

  2. pg_stat_statements: Add local_blk_{read|write}_time

  3. Add local_blk_{read|write}_time I/O timing statistics for local blocks

  4. Rename I/O timing statistics columns to shared_blk_{read|write}_time

  5. Count write times when extending relation files for shared buffers

  6. Add JIT deform_counter

On Tue, Oct 31, 2023 at 08:17:52AM +0900, Michael Paquier wrote:
> Thanks for the input.  I was looking yesterday if this code was
> available somewhere, but couldn't find it..  Until this morning:
> https://gitlab.com/depesz/explain.depesz.com.git

Well, the parser itself is https://gitlab.com/depesz/Pg--Explain/ :)

> And..  It looks like things would become better if we change
> "shared/local" to "shared", because the parsing code seems to have an
> issue once you add a '/'.  All the fields in I/O Timings are
> considered as part of a Node, and they're just included in the output.
> Now, pasting a plan that includes "shared/local" drops entirely the
> string from the output result, so some information is lost.  In short,
> imagine that we have the following string in a node:
> I/O Timings: shared/local write=23.77
> 
> This would show up like that, meaning that the context where the
> write/read timings happened is lost:
> I/O Timings: write=23.77
> 
> If we switch back to "shared", the context would be kept around.  Of
> course, this does not count for all the parsers that may be out
> there, but at least that's something.

Well, if it's possible to deduce what is the meaning in given line,
I can add the logic to do the deduction to parser.

Also, I want to say that I appreciate being looped in the discussion.

Best regards,

depesz