Re: Show comments in \dRp+, \dRs+, and \dX+ psql meta-commands

> On Feb 26, 2026, at 11:32, Fujii Masao <masao(dot)fujii(at)gmail(dot)com> wrote:
>
> On Fri, Feb 20, 2026 at 6:29 PM Jim Jones <jim(dot)jones(at)uni-muenster(dot)de> wrote:
>>
>> Hi Fujii,
>>
>> 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.
>>
>> v2 attached.
>
> Thanks for reviewing and rebasing the patch!
>
> I noticed that I forgot to update the psql help message for \dX+,
> so I've revised the patch. Attached is v3.
>
>> 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
>>
>> ...
>> /* Reduce empty-string to NULL case */
>> if (comment != NULL && strlen(comment) == 0)
>> comment = NULL;
>> ...
>>
>> 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.
>>
>> CREATE SEQUENCE s1;
>> COMMENT ON SEQUENCE s1 IS '';
>> CREATE SEQUENCE s2;
>> COMMENT ON SEQUENCE s2 IS NULL;
>>
>> postgres=# \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)
>>
>> Is it perhaps an undocumented behaviour?
>
> I'm not sure why this behavior isn't documented, but it seems worth
> addressing in a separate documentation patch.
>
> Regards,
>
> --
> 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/