MIME-Version: 1.0
References: <CA+FnnTxFMiA+KMfypfGyY43G2kSx6-t5A351snUMmWC-2Lxvaw@mail.gmail.com>
 <CAKFQuwZOH6BPtaWJKr9jRGxdJt05YtLAZn1s_fYt=uzAASm9CQ@mail.gmail.com>
 <CA+FnnTymNs9_3pBci01_Uu5OTNJFngOhu8_khpmUs88V8kX86Q@mail.gmail.com>
 <71cd4015-9002-4173-bd9a-075f7afb3c20@aklaver.com> <CA+FnnTzx90AzTu07zVGMCYmvBYs_VsL9k2E7eBkzg_rTRwZbeA@mail.gmail.com>
 <5f263a8a-9c30-4118-b410-6e25eafde156@aklaver.com>
In-Reply-To: <5f263a8a-9c30-4118-b410-6e25eafde156@aklaver.com>
From: Igor Korot <ikorot01@gmail.com>
Date: Sun, 19 Apr 2026 20:13:29 -0500
Message-ID: <CA+FnnTxJyrnxR0hhV8T8J7Gb=MZ=OrtrEUcyoMf14-WHKgSb-A@mail.gmail.com>
Subject: Re: List of encodings
To: Adrian Klaver <adrian.klaver@aklaver.com>
Cc: "David G. Johnston" <david.g.johnston@gmail.com>, 
	"pgsql-generallists.postgresql.org" <pgsql-general@lists.postgresql.org>
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable
Archived-At: <https://www.postgresql.org/message-id/CA%2BFnnTxJyrnxR0hhV8T8J7Gb%3DMZ%3DOrtrEUcyoMf14-WHKgSb-A%40mail.gmail.com>
Precedence: bulk

Adrian,

On Sun, Apr 19, 2026 at 7:53=E2=80=AFPM Adrian Klaver <adrian.klaver@aklave=
r.com> wrote:
>
> On 4/19/26 5:19 PM, Igor Korot wrote:
> > Hi, Adrian,
> >
> > On Sun, Apr 19, 2026 at 4:21=E2=80=AFPM Adrian Klaver <adrian.klaver@ak=
laver.com> wrote:
>
> >>> What I noticed is that all encodings are default, as they all have 't=
'
> >>> in the last column.
> >>>
> >>> It's a little confusing...
> >>
> >> Not if you read the docs:
> >>
> >> https://www.postgresql.org/docs/current/catalog-pg-conversion.html
> >>
> >> "The catalog pg_conversion describes encoding conversion functions. Se=
e
> >> CREATE CONVERSION for more information."
> >>
> >> https://www.postgresql.org/docs/current/sql-createconversion.html
> >>
> >> "Conversions that are marked DEFAULT can be used for automatic encodin=
g
> >> conversion between client and server. To support that usage, two
> >> conversions, from encoding A to B and from encoding B to A, must be
> >> defined."
> >
> >  From the https://www.postgresql.org/docs/current/catalog-pg-conversion=
.html:
> >
> > [quote]
> >
> > condefault bool
> >
> > True if this is the default conversion
> > [/quote]
> >
> > So, what info do I trust?
>
> Both.
>
> In your setup all the installed encoding conversion functions are also
> 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)

Thank you.

>
> >
> > Thank you.
> >
>
>
>
> --
> Adrian Klaver
> adrian.klaver@aklaver.com