Horton

Re: making EXPLAIN extensible

Robert Haas <robertmhaas@gmail.com>

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From: Robert Haas <robertmhaas@gmail.com>
To: Andrei Lepikhov <lepihov@gmail.com>
Cc: Sami Imseih <samimseih@gmail.com>, Tom Lane <tgl@sss.pgh.pa.us>, Jeff Davis <pgsql@j-davis.com>, Thom Brown <thom@linux.com>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Date: 2025-03-20T18:24:49Z
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. pg_overexplain: Use PG_MODULE_MAGIC_EXT.

  2. pg_overexplain: Call previous hooks as appropriate.

  3. pg_overexplain: Additional EXPLAIN options for debugging.

  4. Add an additional hook for EXPLAIN option validation.

  5. Add some new hooks so extensions can add details to EXPLAIN.

  6. Make it possible for loadable modules to add EXPLAIN options.

Attachments

On Thu, Mar 20, 2025 at 3:04 AM Andrei Lepikhov <lepihov@gmail.com> wrote:
> I'm sorry, I was confused; previously, the difficulties faced by
> extension developers were always attributed to him (refer to the
> discussion on the selectivity hook). However, now you're introducing a
> hook for a trivial operation that could simply be resolved at the end of
> execution within a per-node hook with tiny inconsistency in output. I'm
> pleased to see a change in the narrative.

It sounds like we're sufficiently in agreement so I've committed the
patch. I agree with you that this could be done within the per-node
hook, but that would be awkward, and this is better. I take note of
your frustration with the difficulty of getting hooks added and to
some extent I share it; on the flip side, there are plenty of
poorly-considered hook proposals, too.

I've rebased my pg_overexplain patch and attach that here.

-- 
Robert Haas
EDB: http://www.enterprisedb.com