Horton

Re: AIX support - alignment issues

Peter Geoghegan <pg@bowt.ie>

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From: Peter Geoghegan <pg@bowt.ie>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Andres Freund <andres@anarazel.de>, Noah Misch <noah@leadboat.com>, PostgreSQL Hackers <pgsql-hackers@postgresql.org>
Date: 2022-07-02T20:12:27Z
Lists: pgsql-hackers 
On Sat, Jul 2, 2022 at 12:22 PM Tom Lane <tgl@sss.pgh.pa.us> wrote:
> Now, it's certainly possible that AIX is the only surviving platform
> that hasn't adopted bug-compatible-with-glibc interpretations of
> POSIX.  But I think the standard is the standard, and we ought to
> stay within it.  So I find value in these fixes.

I imagine that there is strong evolutionary pressure pushing minority
platforms in the direction of bug-compatible-with-glibc. There is
definitely a similar trend around things like endianness and alignment
pickiness. But it wasn't always so.

It seems fair to wonder if AIX bucks the glibc-compatible trend
because it is already on the verge of extinction. If it wasn't just
about dead already then somebody would have gone to the trouble of
making it bug-compatible-with-glibc by now. (To be clear, I'm not
arguing that this is a good thing.)

Maybe it is still worth hanging on to AIX support for the time being,
but it would be nice to have some idea of where we *will* finally draw
the line. If the complaints from Andres aren't a good enough reason
now, then what other hypothetical reasons might be good enough in the
future? It seems fairly likely that Postgres desupporting AIX will
happen (say) at some time in the next decade, no matter what happens
today.

-- 
Peter Geoghegan

Commits

  1. Doc: Acknowledge historically supported CPUs and OSes.

  2. Further tidy-up for old CPU architectures.

  3. Tidy up claimed supported CPUs and OSes.

  4. Remove HP/Intel Itanium support.

  5. Remove HP-UX port.

  6. Reorder subskiplsn in pg_subscription to avoid alignment issues.

  7. Tighten TAP tests' tracking of postmaster state some more.

  8. Reorder pg_sequence columns to avoid alignment issue