Message-ID: <deb797b6766db4fd992454c28d36ba227451493e.camel@j-davis.com>
Subject: Re: Change initdb default to the builtin collation provider
From: Jeff Davis <pgsql@j-davis.com>
To: Laurenz Albe <laurenz.albe@cybertec.at>, Robert Haas
 <robertmhaas@gmail.com>
Cc: pgsql-hackers@postgresql.org
Date: Wed, 11 Mar 2026 14:43:11 -0700
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On Wed, 2026-03-11 at 21:05 +0100, Laurenz Albe wrote:
> The big advantage: if you have only two or three indexes in your
> database that are sorted in a collation other than C, the likelihood
> for index corruption will be way lower.=C2=A0 For example, the unique
> constraint on your part number column that contains values like
> 'XY-1-13*' or '*P1-12_A' (which are pretty likely to be affected by
> the subtle changes in libc collations) will be sorted in the C
> collation, which is just fine for everybody.

Agreed. The collation problems are not because it's used in the handful
of indexes where it's useful; the problems happen when it's used
everywhere.

If a collation version change is detected, and a few indexes need to be
REINDEXed, I think users understand that. But it's pretty difficult to
explain to a user that all text indexes (including primary keys) need
to be reindexed, and that there's no way to keep track of what still
needs to be done.

Regards,
	Jeff Davis