Re: BUG #18964: `ALTER DATABASE ... RESET ...` fails to reset extension parameters that no longer exist

Nathan Bossart <nathandbossart@gmail.com>

From: Nathan Bossart <nathandbossart@gmail.com>

To: Tom Lane <tgl@sss.pgh.pa.us>

Cc: Laurenz Albe <laurenz.albe@cybertec.at>, mert@futo.org, pgsql-bugs@lists.postgresql.org

Date: 2025-08-01T22:01:47Z

Lists: pgsql-bugs

Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →

Allow resetting unknown custom GUCs with reserved prefixes.
- f79ca73d75cb 15.14 landed
- b998ce3272ab 16.10 landed
- 9eb6068fb64c 19 (unreleased) landed
- 7b9674a8b180 18.0 landed
- 39ff056365e4 17.6 landed
Allow ALTER SYSTEM to set unrecognized custom GUCs.
- 2d870b4aeff1 17.0 cited
Disallow setting bogus GUCs within an extension's reserved namespace.
- 88103567cb8f 15.0 cited

Committed.

On Wed, Jul 30, 2025 at 02:13:16PM -0500, Nathan Bossart wrote:
> It applies relatively cleanly down to v15.  The only thing I had to change
> was to replace guc_free() with free() on v15.  I was a little worried about
> changing the signature of check_GUC_name_for_parameter_acl(), but
> codesearch.debian.net doesn't show any outside uses.

I ended up skipping the back-patch of commit 2d870b4 to avoid the ABI
breakage.  That means ALTER SYSTEM remains broken for this use-case on v15
and v16, but IIUC it's already pretty broken in this area, so I'm not sure
we care too much.

-- 
nathan