Horton

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

Masahiko Sawada <sawada.mshk@gmail.com>

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From: Masahiko Sawada <sawada.mshk@gmail.com>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Noah Misch <noah@leadboat.com>, Joe Conway <mail@joeconway.com>, Peter Eisentraut <peter@eisentraut.org>, Alexander Korotkov <aekorotkov@gmail.com>, "Guo, Adam" <adamguo@amazon.com>, "pgsql-hackers@lists.postgresql.org" <pgsql-hackers@lists.postgresql.org>, Nathan Bossart <nathandbossart@gmail.com>, Jim Mlodgenski <jimmy76@gmail.com>
Date: 2024-09-10T05:18:49Z
Lists: pgsql-hackers 
On Mon, Sep 9, 2024 at 4:42 PM Tom Lane <tgl@sss.pgh.pa.us> wrote:
>
> Masahiko Sawada <sawada.mshk@gmail.com> writes:
> > When do we set the byte on the primary server? If it's the first time
> > to use the GIN index, secondary servers would have to wait for the
> > primary to use the GIN index, which could be an unpredictable time or
> > it may never come depending on index usages. Probably we can make
> > pg_upgrade set the byte in the meta page of GIN indexes that use the
> > gin_trgm_ops.
>
> Hmm, perhaps.  That plus set-it-during-index-create would remove the
> need for dynamic update like I suggested.  So very roughly the amount
> of complexity would balance out.

Yes, I think your set-it-during-index-create would be necessary.

>  Do you have an idea for how we'd get
> this to happen during pg_upgrade, exactly?

What I was thinking is that we have "pg_dump --binary-upgrade" emit a
function call, say "SELECT binary_upgrade_update_gin_meta_page()" for
each GIN index, and the meta pages are updated when restoring the
schemas.

Regards,

--
Masahiko Sawada
Amazon Web Services: https://aws.amazon.com

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.