Horton

Re: making EXPLAIN extensible

Peter Eisentraut <peter@eisentraut.org>

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From: Peter Eisentraut <peter@eisentraut.org>
To: Robert Haas <robertmhaas@gmail.com>, Tom Lane <tgl@sss.pgh.pa.us>
Cc: Jeff Davis <pgsql@j-davis.com>, Thom Brown <thom@linux.com>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Date: 2025-03-07T14:38:15Z
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.

On 06.03.25 21:23, Robert Haas wrote:
> On Wed, Mar 5, 2025 at 4:38 PM Tom Lane <tgl@sss.pgh.pa.us> wrote:
>> v4 has addressed most of my nitpicks, but you still have typedefs
>> for ExplainState in both header files.  My bet is that at least
>> one buildfarm animal will complain about that.  I could be wrong
>> though, maybe all such compilers are in disuse now.
> 
> Ugh, I suck at this, sorry. Adjusted in v5. It's hard to avoid the
> conclusion that our IWYU configuration must be fairly lenient, because
> every change seems to surface more source files that are depending on
> indirect includes.

Just to clarify this:  Nobody has gone through and used IWYU to clean up 
indirect includes, as you appear to imagine here.  My recent IWYU work 
was, besides putting some infrastructure in place, to clean up includes 
that are completely unneeded.  Indirect includes cleanup is a different 
project that is not currently happening, AFAIK.

Also, benign typedef redefinitions are a C11 feature.  In practice, all 
compilers currently in play support it, and the only problem you'll get 
is from the buildfarm members that are explicitly set up to warn about 
accidental C11 use.  We could probably have a discussion about that, but 
for this patch set, it's probably better to just deal with the status quo.