Jeff Davis <pgsql@j-davis.com> writes:
> On Tue, 2024-07-23 at 16:07 -0400, Tom Lane wrote:
>> Well, it depends on which libc collation you have in mind. I was
>> thinking of a libc-supplied C.UTF-8 collation, which I would expect
>> to behave the same as pg_c_utf8, modulo which Unicode version it's
>> based on.
> Daniel Vérité documented[1] cases where the libc C.UTF-8 locale changed
> the *sort* behavior, thereby affecting primary keys.
Ouch. But we didn't establish whether that was an ancient bug,
or something likely to happen again. (In any case, that surely
reinforces the point that we can expect pg_c_utf8 to be more
stable than any previously-available alternative.)
regards, tom lane