Horton

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

Laurenz Albe <laurenz.albe@cybertec.at>

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From: Laurenz Albe <laurenz.albe@cybertec.at>
To: Nathan Bossart <nathandbossart@gmail.com>
Cc: Tom Lane <tgl@sss.pgh.pa.us>, mert@futo.org, pgsql-bugs@lists.postgresql.org
Date: 2025-07-24T21:06:57Z
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 →

  1. Allow resetting unknown custom GUCs with reserved prefixes.

  2. Allow ALTER SYSTEM to set unrecognized custom GUCs.

  3. Disallow setting bogus GUCs within an extension's reserved namespace.

On Thu, 2025-07-24 at 11:30 -0500, Nathan Bossart wrote:
> On Tue, Jul 22, 2025 at 04:27:24AM +0200, Laurenz Albe wrote:
> 
> > There is still one piece missing in my opinion:
> > 
> >   ALTER SYSTEM RESET testext.swap_limit;
> >   ERROR:  invalid configuration parameter name "testext.swap_limit"
> >   DETAIL:  "testext" is a reserved prefix.
> > 
> > I think that this case should work like the others.
> 
> Good catch.  This should be fixed in v3.

Check.

> > I'd like to see regression tests for this, but I am not sure how
> > to best devise them.
> > One idea would be to stick them into the regression tests of some
> > contrib module, even though it is not the perfect place.
> 
> Added in v3.

Great!  The regression test works fine on my Linux machine.

> --- /dev/null
> +++ b/contrib/auto_explain/sql/alter_reset.sql
> [...]
> +SELECT current_database() AS datname \gset
> +CREATE ROLE regress_ae_role;
> +
> +ALTER DATABASE :datname SET auto_explain.bogus = 1;
> +ALTER ROLE regress_ae_role SET auto_explain.bogus = 1;
> +ALTER ROLE regress_ae_role IN DATABASE :datname SET auto_explain.bogus = 1;
> +ALTER SYSTEM SET auto_explain.bogus = 1;
> +
> +LOAD 'auto_explain';
> +
> +ALTER DATABASE :datname RESET auto_explain.bogus;
> +ALTER ROLE regress_ae_role RESET auto_explain.bogus;
> +ALTER ROLE regress_ae_role IN DATABASE :datname RESET auto_explain.bogus;

That is perhaps a rediculous quibble, but shouldn't that be :"datname"?
I guess the regression test database will always have a proper name...

Anyway, I'll mark the patch as "ready for committer".

Yours,
Laurenz Albe