Date: Wed, 24 Apr 2024 23:39:37 -0400
From: Bruce Momjian <bruce@momjian.us>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Peter Eisentraut <peter@eisentraut.org>,
	Sriram RK <sriram.rk@outlook.com>,
	Andres Freund <andres@anarazel.de>,
	Thomas Munro <thomas.munro@gmail.com>,
	Noah Misch <noah@leadboat.com>,
	Alvaro Herrera <alvherre@alvh.no-ip.org>,
	"pgsql-hackers@postgresql.org" <pgsql-hackers@postgresql.org>,
	"tvk1271@gmail.com" <tvk1271@gmail.com>,
	Heikki Linnakangas <hlinnaka@iki.fi>
Subject: Re: AIX support
Message-ID: <ZinQeSfk5rOs49ha@momjian.us>
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On Sat, Apr 20, 2024 at 12:25:47PM -0400, Tom Lane wrote:
> > I can see several ways going forward:
> > 1. We revert the removal of AIX support and carry on with the status quo 
> > ante.  (The removal of AIX is a regression; it is timely and in scope 
> > now to revert the change.)
> > 2. Like (1), but we consider that notice has been given, and we will 
> > remove it early in PG18 (like August) unless the situation improves.
> > 3. We leave it out of PG17 and consider a new AIX port for PG18 on its 
> > own merits.
> 
> Andres has ably summarized the reasons why the status quo ante was
> getting untenable.  The direct-I/O problem could have been tolerable
> on its own, but in reality it was the straw that broke the camel's
> back so far as our willingness to maintain AIX support went.  There
> were just too many hacks and workarounds for too many problems,
> with too few people interested in looking for better answers.
> 
> So I'm totally not in favor of #1, at least not without some hard
> commitments and follow-through on really cleaning up the mess
> (which maybe looks more like your #2).  What's needed here, as
> you said, is for someone with a decent amount of expertise in
> modern AIX to review all the issues.  Maybe framing that as a
> "new port" per #3 would be a good way to think about it.  But
> I don't want to just revert the AIX-ectomy and continue drifting.
> 
> On the whole, it wouldn't be the worst thing in the world if PG 17
> lacks AIX support but that comes back in PG 18.  That approach would
> solve the schedule-crunch aspect and give time for considered review
> of how many of the hacks removed in 0b16bb877 really need to be put
> back, versus being obsolete or amenable to a nicer solution in
> late-model AIX.  If we take a "new port" mindset then it would be
> totally reasonable to say that it only supports very recent AIX
> releases, so I'd hope at least some of the cruft could be removed.

I agree that targeting PG 18 for a new-er AIX port is the reasonable
approach.  If there is huge demand, someone can create an AIX fork for
PG 17 using the reverted patches --- yeah, lots of pain there, but we
have carried the AIX pain for too long with too little support.

-- 
  Bruce Momjian  <bruce@momjian.us>        https://momjian.us
  EDB                                      https://enterprisedb.com

  Only you can decide what is important to you.