Content-Type: text/plain;
	charset=utf-8
Mime-Version: 1.0 (Mac OS X Mail 16.0 \(3864.400.21\))
Subject: Re: Show comments in \dRp+, \dRs+, and \dX+ psql meta-commands
From: Chao Li <li.evan.chao@gmail.com>
In-Reply-To: <CAHGQGwFJKg-aT5vajSU1v_B4K129u_SjZ3EGGHFSBhW967gcMA@mail.gmail.com>
Date: Thu, 26 Feb 2026 13:34:02 +0800
Cc: Jim Jones <jim.jones@uni-muenster.de>,
 PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Content-Transfer-Encoding: quoted-printable
Message-Id: <E65FA3EA-4AB5-429C-818F-3037C5E8E390@gmail.com>
References: <CAHGQGwGL4JqiKA26fnGx-cTM=VzoTs_uzqejvj4Fawyr4uLUUw@mail.gmail.com>
 <82b25785-0dc1-46d6-93ac-ce385a3a0bfc@uni-muenster.de>
 <CAHGQGwFJKg-aT5vajSU1v_B4K129u_SjZ3EGGHFSBhW967gcMA@mail.gmail.com>
To: Fujii Masao <masao.fujii@gmail.com>
Archived-At: <https://www.postgresql.org/message-id/E65FA3EA-4AB5-429C-818F-3037C5E8E390%40gmail.com>
Precedence: bulk


> On Feb 26, 2026, at 11:32, Fujii Masao <masao.fujii@gmail.com> wrote:
>=20
> On Fri, Feb 20, 2026 at 6:29=E2=80=AFPM Jim Jones =
<jim.jones@uni-muenster.de> wrote:
>>=20
>> Hi Fujii,
>>=20
>> Due to recent changes in describe.c and subscription.out, v1 was no
>> longer applying. I rebased it just to test the feature -- feel free =
to
>> revert it.
>>=20
>> v2 attached.
>=20
> Thanks for reviewing and rebasing the patch!
>=20
> I noticed that I forgot to update the psql help message for \dX+,
> so I've revised the patch. Attached is v3.
>=20
>> One unrelated thing caught my attention though: NULLs and empty =
strings
>> are both displayed as NULL, which is expected according to
>> CreateComments() in comment.c
>>=20
>> ...
>> /* Reduce empty-string to NULL case */
>> if (comment !=3D NULL && strlen(comment) =3D=3D 0)
>>  comment =3D NULL;
>> ...
>>=20
>> However, I couldn't find anything in the docs that clearly says that
>> it's going to be the case -- at least not in comment.sgml.
>>=20
>> CREATE SEQUENCE s1;
>> COMMENT ON SEQUENCE s1 IS '';
>> CREATE SEQUENCE s2;
>> COMMENT ON SEQUENCE s2 IS NULL;
>>=20
>> postgres=3D# \ds+
>> List of sequences
>> -[ RECORD 1 ]-----------
>> Schema      | public
>> Name        | s1
>> Type        | sequence
>> Owner       | jim
>> Persistence | permanent
>> Size        | 8192 bytes
>> Description | (null)
>> -[ RECORD 2 ]-----------
>> Schema      | public
>> Name        | s2
>> Type        | sequence
>> Owner       | jim
>> Persistence | permanent
>> Size        | 8192 bytes
>> Description | (null)
>>=20
>> Is it perhaps an undocumented behaviour?
>=20
> I'm not sure why this behavior isn't documented, but it seems worth
> addressing in a separate documentation patch.
>=20
> Regards,
>=20
> --=20
> Fujii Masao
> <v3-0001-psql-Show-comments-in-dRp-dRs-and-dX-psql-meta-co.patch>

I applied v3 locally, built it and played a little bit, then reviewed =
the code change. Everything looks good to me.

Best regards,
--
Chao Li (Evan)
HighGo Software Co., Ltd.
https://www.highgo.com/