Message-ID: <ab925f69-5f9d-f85e-b87c-bd2a44798659@joeconway.com>
Date: Tue, 6 Jun 2023 15:21:25 -0400
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Subject: Re: Order changes in PG16 since ICU introduction
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To: Jeff Davis <pgsql@j-davis.com>, Daniel Verite <daniel@manitou-mail.org>
Cc: Peter Eisentraut <peter.eisentraut@enterprisedb.com>,
 Andrew Gierth <andrew@tao11.riddles.org.uk>, Tom Lane <tgl@sss.pgh.pa.us>,
 pgsql-hackers@lists.postgresql.org
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 <f8d09d8f3d53daa9cdb446d021fe33d6ff7f1ee3.camel@j-davis.com>
From: Joe Conway <mail@joeconway.com>
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On 6/6/23 15:18, Jeff Davis wrote:
> On Tue, 2023-06-06 at 15:09 +0200, Daniel Verite wrote:
>> FWIW I don't quite see how 0001 improve things or what problem it's
>> trying to solve.
> 
> The word "locale" is generic, so we need to make LOCALE/--locale apply
> to whatever provider is being used. If "locale" only applies to libc,
> using ICU will always be confusing and never be on the same level as
> libc, let alone the preferred provider.


Agree 100%

> The locale "C" is a special case, documented as a non-locale. So, if
> LOCALE/--locale apply to ICU, then either ICU needs to handle locale
> "C" in the expected way (v8 patch series); or when we see locale "C" we
> need to somehow change the provider into something that can handle it
> (v6 patch series changes it to the "none" provider).

+1 to the latter approach

> Please let me know if you disagree with the goal or the reasoning here.
> If so, please explain where you think we should end up, because the
> status quo does not seem great to me.

also +1

>> 0001 creates exceptions throughout the code so that when an ICU
>> collation has a locale name "C" or "POSIX" then it does not behave
>> like an ICU collation, even though pg_collation.collprovider='i'
>> To me it's neither desirable nor necessary that a collation that
>> has collprovider='i' is diverted to non-ICU semantics.
> 
> It's not very principled, but it matches what libc does.

Makes sense to me

-- 
Joe Conway
PostgreSQL Contributors Team
RDS Open Source Databases
Amazon Web Services: https://aws.amazon.com