Feedback-ID: i76984098:Fastmail
Message-ID: <603f35e6-32b2-4044-bbfb-5e70bba5164b@aklaver.com>
Date: Tue, 17 Jun 2025 09:55:14 -0700
MIME-Version: 1.0
User-Agent: Mozilla Thunderbird
Subject: Re: Changing locale of an existing database
To: Marcin Gozdalik <gozdal@gmail.com>, pgsql-general@postgresql.org
References: <CADu1mRP=rTC2WX=-EWqCX-CWjp9q09xxuEkK=2Se3wx1HasSkQ@mail.gmail.com>
Content-Language: en-US
From: Adrian Klaver <adrian.klaver@aklaver.com>
In-Reply-To: <CADu1mRP=rTC2WX=-EWqCX-CWjp9q09xxuEkK=2Se3wx1HasSkQ@mail.gmail.com>
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 8bit
Archived-At: <https://www.postgresql.org/message-id/603f35e6-32b2-4044-bbfb-5e70bba5164b%40aklaver.com>
Precedence: bulk

On 6/17/25 09:20, Marcin Gozdalik wrote:
> Hi
> 
> I am using PostgreSQL 17 and would like to take advantage of performance 
> and stability across OS updates of builtin C.UTF-8 locale.
> I have a cluster with a DB created with en_US.UTF-8 libc locale. I would 
> like to migrate the DB to C.UTF-8. Ideally there'd be an "ALTER DATABASE 
> ... SET LOCALE ..." command that would take care of it but it seems it 
> doesn't exist. I was thinking that I could change the collation of all 
> TEXT/CHAR/VARCHAR columns in all the tables to pg_c_utf8, REINDEX all 
> those columns and change the default locale in the pg_database table.
> 
> Is it a sensible plan? Am I missing some steps? I can't find any 
> reference to anybody doing that before or discouraging it.

How big a database are we talking about?

To me it would seem easier to create a new database with new locale and 
do either a pg_dump/pg_restore or logical replication to the new 
instance. Of course this may depend on the answer to the question above.

> 
> Thanks,
> Marcin
> 
> -- 
> Marcin Gozdalik

-- 
Adrian Klaver
adrian.klaver@aklaver.com