Re: Choosing default collation/ctype
Laurenz Albe <laurenz.albe@cybertec.at>
From: Laurenz Albe <laurenz.albe@cybertec.at>
To: Daniel Verite <daniel@manitou-mail.org>
Cc: Ron Johnson <ronljohnsonjr@gmail.com>, pgsql-general@lists.postgresql.org
Date: 2026-05-04T20:45:16Z
Lists: pgsql-general
On Mon, 2026-05-04 at 21:34 +0200, Daniel Verite wrote:
> Laurenz Albe wrote:
>
> > > Then choose UTF8.
> >
> > Right! And I recommend "C" for the collation.
>
> Yet the "C" collation is unsuitable for handling character types
> beyond ASCII.
> For instance, it considers that accented letters are not letters,
> so upper('été') is 'éTé' instead of 'ÉTÉ', and 'é' ~ '\w' is false.
>
> C.UTF-8 solves that, and since Postgres 17, it's available for all operating
> systems with the builtin provider.
> So if you target Postgres 17+, C.UTF-8 from the builtin provider is
> a better choice for UTF-8 databases than "C" .
Yes, "builtin" and the "C" collation is the best default value.
Yours,
Laurenz Albe