Horton

Re: pg_dump versus ancient server versions

Robert Haas <robertmhaas@gmail.com>

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From: Robert Haas <robertmhaas@gmail.com>
To: Alvaro Herrera <alvherre@alvh.no-ip.org>
Cc: Tom Lane <tgl@sss.pgh.pa.us>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>, Andres Freund <andres@anarazel.de>
Date: 2021-10-24T20:45:20Z
Lists: pgsql-hackers 
On Fri, Oct 22, 2021 at 7:51 PM Alvaro Herrera <alvherre@alvh.no-ip.org> wrote:
> I just tried to build 9.1.  My config line there doesn't have ssl, but I
> do get this in the compile stage:

Hmm.

You know, one thing we could think about doing is patching some of the
older branches to make them compile on modern machines. That would not
only be potentially useful for people who are upgrading from ancient
versions, but also for hackers trying to do research on the origin of
bugs or performance problems, and also for people who are trying to
maintain some kind of backward compatibility or other and want to test
against old versions.

I don't know whether that's really worth the effort and I expect Tom
will say that it's not. If he does say that, he may be right. But I
think if I were trying to extract my data from an old 7.4 database, I
think I'd find it a lot more useful if I could make 9.0 or 9.2 or
something compile and talk to it than if I had to use v15 and hope
that held together somehow. It doesn't really make sense to try to
keep compatibility of any sort with versions we can no longer test
against.

--
Robert Haas
EDB: http://www.enterprisedb.com

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