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From: Igor Korot <ikorot01@gmail.com>
Date: Sun, 19 Apr 2026 17:09:34 -0500
Message-ID: <CA+FnnTwPJL0vFWh7CgNpp_U9W2edPtv0+sPQkWS2xK=wRytaog@mail.gmail.com>
Subject: Re: List of encodings
To: "David G. Johnston" <david.g.johnston@gmail.com>, Tom Lane <tgl@sss.pgh.pa.us>
Cc: "pgsql-generallists.postgresql.org" <pgsql-general@lists.postgresql.org>
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Hi, ALL,

My question comes from the fact that "Character Set", LC_COLLATE and
LC_CTYPE can be
used here: https://www.postgresql.org/docs/18/sql-createdatabase.html
However its a little bit confusing.

The character set should define the collate and the CType things. But
according to the docs
it looks like its vice versa.
Also, there is no reference on where do I get the corresponding values
for LC_COLLATE and LC_CTYPE.

Thank you,


On Sun, Apr 19, 2026 at 3:27=E2=80=AFPM Igor Korot <ikorot01@gmail.com> wro=
te:
>
> Hi, David,
>
> On Sat, Apr 18, 2026 at 2:19=E2=80=AFAM David G. Johnston
> <david.g.johnston@gmail.com> wrote:
> >
> > On Friday, April 17, 2026, Igor Korot <ikorot01@gmail.com> wrote:
> >>
> >> Hi, ALL,
> >> Does the list shown in
> >> https://www.postgresql.org/docs/current/multibyte.html#MULTIBYTE-CHARS=
ET-SUPPORTED
> >> stored somewhere in INFORMATION_SCHEMA?
> >
> >
> > This wouldn=E2=80=99t be under the purview of information schema.  You =
can find pg-specific pieces though:
> >
> > https://www.postgresql.org/docs/current/catalog-pg-conversion.html
> >
> > Note the function used to convert ids to names.
>
> Tried the following query:
>
> SELECT conname AS name, pg_encoding_to_char( conforencoding ) AS
> encoding, condefault AS default FROM pg_conversion ORDER BY encoding;
>
> and got following results (for simplicity I will post only couple of rows=
):
>
>  big5_to_utf8                   | BIG5           | t
>  big5_to_euc_tw                 | BIG5           | t
>  big5_to_mic                    | BIG5           | t
>  euc_cn_to_mic                  | EUC_CN         | t
>  euc_cn_to_utf8                 | EUC_CN         | t
>  euc_jis_2004_to_shift_jis_2004 | EUC_JIS_2004   | t
>  euc_jis_2004_to_utf8           | EUC_JIS_2004   | t
>  euc_jp_to_mic                  | EUC_JP         | t
>  euc_jp_to_sjis                 | EUC_JP         | t
>  euc_jp_to_utf8                 | EUC_JP         | t
>  euc_kr_to_utf8                 | EUC_KR         | t
>  euc_kr_to_mic                  | EUC_KR         | t
>  euc_tw_to_big5                 | EUC_TW         | t
>  euc_tw_to_utf8                 | EUC_TW         | t
>  euc_tw_to_mic                  | EUC_TW         | t
>
> What I noticed is that all encodings are default, as they all have 't'
> in the last column.
>
> It's a little confusing...
>
> Thx for the help.
>
> >
> >>
> >>
> >> Or is it hard coded inside the PostgreSQL codebase?
> >
> >
> >  Yes.  Doesn=E2=80=99t preclude exposing it via SQL but we don=E2=80=99=
t do so directly.
> >
> > David J.