Horton

Re: pg_dump versus ancient server versions

Tom Lane <tgl@sss.pgh.pa.us>

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From: Tom Lane <tgl@sss.pgh.pa.us>
To: "David G. Johnston" <david.g.johnston@gmail.com>
Cc: PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>, Andres Freund <andres@anarazel.de>
Date: 2021-10-22T23:30:25Z
Lists: pgsql-hackers 
"David G. Johnston" <david.g.johnston@gmail.com> writes:
> On Fri, Oct 22, 2021 at 3:42 PM Tom Lane <tgl@sss.pgh.pa.us> wrote:
>> Anyway, I think the default answer is "revert 92316a458 and keep the
>> compatibility goalposts where they are".  But I wanted to open up a
>> discussion to see if anyone likes the other approach better.

> ... IMO, the bar for this kind of situation should be 10 releases at
> most - 5 of which would be in support at the time the patch goes in.  We
> don't have to actively drop support of older stuff but anything older
> shouldn't be preventing new commits.

Yeah.  I checked into when it was that we dropped pre-8.0 support
from pg_dump, and the answer is just about five years ago (64f3524e2).
So moving the bar forward by five releases isn't at all out of line.
8.4 would be eight years past EOL by the time v15 comes out.

One of the arguments for the previous change was that it was getting
very hard to build old releases on modern platforms, thus making it
hard to do any compatibility testing.  I believe the same is starting
to become true of the 8.x releases, though I've not tried personally
to build any of them in some time.  (The executables I'm using for
them date from 2014 or earlier, and have not been recompiled in
subsequent platform upgrades ...)  Anyway it's definitely not free
to continue to support old source server versions.

			regards, tom lane

Commits

  1. Remove psql support for server versions preceding 9.2.

  2. Clean up some more freshly-dead code in pg_dump and pg_upgrade.

  3. Remove pg_dump's --no-synchronized-snapshots switch.

  4. Remove pg_upgrade support for upgrading from pre-9.2 servers.

  5. Remove pg_dump/pg_dumpall support for dumping from pre-9.2 servers.

  6. Suppress -Warray-bounds warning in 9.2's xlog.c.

  7. Suppress -Wformat-overflow warnings in 9.2's xml.c.

  8. Disable -Wsometimes-uninitialized warnings in the 9.2 branch.

  9. Fix function return type confusion

  10. Fix compiler warning

  11. Silence another gcc 11 warning.

  12. Suppress uninitialized-variable warning in guc.c.

  13. Suppress -Warray-parameter warnings in pgcrypto/sha2.c.

  14. Reformat imath.c macro to remove -Wmisleading-indentation warnings.

  15. Clean up compilation warnings coming from PL/Perl with clang-12~

  16. Make ecpg's rjulmdy() and rmdyjul() agree with their declarations.

  17. Use -Wno-format-truncation and -Wno-stringop-truncation, if available.

  18. Make pg_upgrade's test.sh less chatty.

  19. Add checks for valid multibyte character length in UtfToLocal, LocalToUtf.

  20. Use return instead of exit() in configure

  21. Add support for Visual Studio 2019 in build scripts