Date: Fri, 20 Jun 2025 16:20:25 -0500
From: Nathan Bossart <nathandbossart@gmail.com>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: mert@futo.org, pgsql-bugs@lists.postgresql.org
Subject: Re: BUG #18964: `ALTER DATABASE ... RESET ...` fails to reset
 extension parameters that no longer exist
Message-ID: <aFXQmZ2sveFAwdjY@nathan>
References: <18964-ba09dea8c98fccd6@postgresql.org>
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On Fri, Jun 20, 2025 at 04:24:41PM -0400, Tom Lane wrote:
> In the case at hand, where the prefix is known but the parameter
> isn't, I think we could safely assume that the setting is either
> a mistake (probably installed while the extension wasn't loaded)
> or the described case of a parameter the extension no longer
> uses.  Either way it seems safe to allow RESET with suitable
> privileges on the target DB and/or role.

I'm a little hesitant to consider opening this up too much.  For example,
what if someone accidentally downgrades the library temporarily and a GUC
definition disappears, or one version of the library removes a parameter
and a future one adds it back (due to user backlash)?  Maybe those
situations are too contrived/unlikely to worry about, though.

> If the prefix is not known, then we're really flying blind.
> It looks like we assume the parameter might be SUSET and therefore
> allow both ALTER DB/ROLE SET and RESET only to superusers.
> I'm hesitant to relax that case.

IIUC we also check pg_parameter_acl in this case, but I agree that we don't
want to relax this any further.

-- 
nathan