Date: Thu, 22 Jan 2026 09:42:50 -0800
From: Noah Misch <noah@leadboat.com>
To: Mark Dilger <mark.dilger@enterprisedb.com>
Cc: Nitin Motiani <nitinmotiani@google.com>,
	Andres Freund <andres@anarazel.de>, pgsql-hackers@postgresql.org
Subject: Re: Inval reliability, especially for inplace updates
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On Thu, Jan 22, 2026 at 07:53:21AM -0800, Mark Dilger wrote:
> On Wed, Jan 21, 2026 at 9:47 AM Noah Misch <noah@leadboat.com> wrote:
> > Based on your experience, I probably should encourage packagers to do an
> > early check of the packages they build, especially if they build tableam
> > modules not found in PGXN.  How do you see it?
> 
> I don't know what you mean by "early".  18.2 hasn't stamped yet.  18.1
> doesn't have the change.  So, I'd say that I'm building pretty early, and I
> noticed the change will be coming in 18.2.

I'll probably say:

  If you've tested your packaging builds against REL_17_STABLE and
  REL_18_STABLE since 2025-12-16 *or* you package only modules present in
  PGXN, you can stop reading.

  Mark Dilger reported non-PGXN tableam modules that needed changes to cope
  with back-patched signature changes in functions
  CacheInvalidateHeapTupleInplace() (commit 06b030e) and
  PrepareToInvalidateCacheTuple() (commit 2e58802).  Consider trying a rebuild
  against REL_17_STABLE and REL_18_STABLE now, so you learn about any similar
  need for changes in your modules.

> Oh, I don't mean to question the overall purpose of the patch.  I was
> questioning whether it needed to have breaking changes which are mere "code
> cleanup".  The change to CacheInvalidateHeapTupleInplace to remove the
> unused third argument seemed inappropriate for backpatching, so I spoke up
> before 18.2 is stamped.  Doing this one piece of code cleanup in the back
> branches will cause a lot of packaging pain for no real benefit.

Is the source code for one of these modules published?  I'm not picturing how
a module could need a CacheInvalidateHeapTupleInplace() call, so your code may
illuminate that for me.

If you upload one of these modules to PGXN, my scans before future ABI breaks
will find its calls and will block avoidable ABI breaks like the
CacheInvalidateHeapTupleInplace() one.