Horton

Re: pg_trgm comparison bug on cross-architecture replication due to different char implementation

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

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From: Tom Lane <tgl@sss.pgh.pa.us>
To: Masahiko Sawada <sawada.mshk@gmail.com>
Cc: "Guo, Adam" <adamguo@amazon.com>, "pgsql-hackers@lists.postgresql.org" <pgsql-hackers@lists.postgresql.org>
Date: 2024-04-30T03:37:21Z
Lists: pgsql-hackers 
Masahiko Sawada <sawada.mshk@gmail.com> writes:
> On Tue, Apr 23, 2024 at 11:57 PM Tom Lane <tgl@sss.pgh.pa.us> wrote:
>> Reject as not a bug.  Discourage people from thinking that physical
>> replication will work across architectures.

> While cross-arch physical replication is not supported, I think having
> architecture dependent differences is not good and It's legitimate to
> fix it. FYI the 'char' data type comparison is done as though char is
> unsigned. I've attached a small patch to fix it. What do you think?

I think this will break existing indexes that are working fine.
Yeah, it would have been better to avoid the difference, but
it's too late now.

			regards, tom lane

Commits

  1. pg_upgrade: Check for the expected error message in TAP tests.

  2. Fix a typo in 005_char_signedness.pl test.

  3. Add test 005_char_signedness.pl to meson.build.

  4. Fix an issue with index scan using pg_trgm due to char signedness on different architectures.

  5. pg_upgrade: Add --set-char-signedness to set the default char signedness of new cluster.

  6. pg_upgrade: Preserve default char signedness value from old cluster.

  7. pg_resetwal: Add --char-signedness option to change the default char signedness.

  8. Add default_char_signedness field to ControlFileData.

  9. Remove unneeded nbtree array preprocessing assert.