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Subject: Re: Prevent remote libpq notices from being sent to clients
From: Chao Li <li.evan.chao@gmail.com>
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 <CAOYmi+nqE5ZoSEi9gJjVtEYS9xjVmELpfgedm5ajaEdSa=Hbpw@mail.gmail.com>
Date: Sat, 6 Jun 2026 09:10:46 +0800
Cc: Tom Lane <tgl@sss.pgh.pa.us>,
 Fujii Masao <masao.fujii@gmail.com>,
 Postgres hackers <pgsql-hackers@lists.postgresql.org>,
 vignesh C <vignesh21@gmail.com>
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To: Jacob Champion <jacob.champion@enterprisedb.com>
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> On Jun 5, 2026, at 23:20, Jacob Champion =
<jacob.champion@enterprisedb.com> wrote:
>=20
> On Fri, Jun 5, 2026 at 7:43=E2=80=AFAM Tom Lane <tgl@sss.pgh.pa.us> =
wrote:
>> Also, I don't buy the argument that this is a "leak": if the remote
>> server was willing to send the message to its client, it doesn't =
think
>> that the message is security-critical.
>=20
> I don't think the remote gets to decide that, in general. It's up to
> the middle layer to know whether it's operating at the same level of
> trust as the end client.
>=20
> --Jacob

Thanks to all for the input. It looks like people have different =
opinions on this topic. BTW, I realized that my previous wording of =
"leak" was too strong, sorry about that.

Here, I think the main concern is that this is an =E2=80=9Cunintentional" =
user-visible behavior change. I went through the original discussion =
thread [1], and I don't see this behavior change being explicitly =
discussed. I am not against Fujii's idea that emitting a remote WARNING =
to the client could be helpful, and I also like Tom's idea of mapping =
the remote severity to the local log level. But if we really want to do =
that, I think we need a dedicated discussion, and that seems too late =
for v19. Also, if we eventually decide to change the client-visible =
behavior, I think we should document it explicitly.

How about preserving the old client-visible behavior for v19?  I can add =
this topic to my TODO list and follow up with this work for v20.

[1] =
https://postgr.es/m/CALDaNm2xsHpWRtLm-VL_HJCsaE3+1Y_n-jDEAr3-suxVqc3xoQ@ma=
il.gmail.com

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