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From: Igor Korot <ikorot01@gmail.com>
Date: Mon, 20 Apr 2026 19:47:12 -0700
Message-ID: <CA+FnnTx_RXR_3CY6TbO8ov+Ky+VoiDEopmBisPMA9+cWoZqAMw@mail.gmail.com>
Subject: Re: List of encodings
To: Ron Johnson <ronljohnsonjr@gmail.com>
Cc: "pgsql-generallists.postgresql.org" <pgsql-general@lists.postgresql.org>
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My understanding is that if I have 3 "BIG5" encodings, only one can be
a default.

And if you want you can choose the other 2, but selecting "BIG5" will
make only one
to be selected by default.
That is why it is called "default" ;-)

Thank you.

On Mon, Apr 20, 2026 at 7:42=E2=80=AFPM Igor Korot <ikorot01@gmail.com> wro=
te:
>
> Hi, ALL,
>
>
> On Sun, Apr 19, 2026 at 8:32=E2=80=AFPM Ron Johnson <ronljohnsonjr@gmail.=
com> wrote:
> >
> >
> >
> > On Sun, Apr 19, 2026 at 9:13=E2=80=AFPM Igor Korot <ikorot01@gmail.com>=
 wrote:
> >>
> >> [snip]
> >> >
> >> > In your setup all the installed encoding conversion functions are al=
so
> >> > the default for those conversions. It is possible to create/install =
a
> >> > conversion function that is not the default.
> >>
> >> So, let's say I chose "BIG5"".
> >>
> >> As stated the table contains:
> >>
> >>  big5_to_utf8                   | BIG5           | t
> >>  big5_to_euc_tw                 | BIG5           | t
> >>  big5_to_mic                    | BIG5           | t
> >>
> >> Since all 3 are default character sets, which one would be chosen?
> >> (in the context of CREATE DATABASE)
> >
> >
> > Does CREATE DATABASE convert text?  (I think you might be misunderstand=
ing the purpose of the pg_conversion table.)
>
> No it does not.
>
> But it has an option that can be chosen and supplied to the command...
>
> So when I write "CREATE DATABASE mydb ECODING =3D BIG5", what will happen=
?
>
> Moreover, I'm curious - if I chose "BIG5", there are only number of
> available collate/ctype pairs.
> How do I choose which one to present to the user.
> Because there is not one default "BIG5" - there are 3 default "BIG5"s.
>
> Thank you.
>
> >
> > Wouldn't it only convert text when a client is inserting text of encodi=
ng X into a table with encoding Y?
> >
> > ISTM that pg_conversion says whether PG knows how to convert from X to =
Y, not the encoding scheme you defined when creating the db.
> >
> > --
> > Death to <Redacted>, and butter sauce.
> > Don't boil me, I'm still alive.
> > <Redacted> lobster!