Re: Allow GUC settings in CREATE SUBSCRIPTION CONNECTION to take effect

Fujii Masao <masao.fujii@gmail.com>

From: Fujii Masao <masao.fujii@gmail.com>

To: Chao Li <li.evan.chao@gmail.com>

Cc: PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>

Date: 2025-11-25T11:30:35Z

Lists: pgsql-hackers

Commits

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

Add TAP test for GUC settings passed via CONNECTION in logical replication.
- ec8d91c7e78c 15.16 landed
- 67edd54f0639 16.12 landed
- 358784645eb8 17.8 landed
- 6ec596815125 18.2 landed
- 5f13999aa11d 19 (unreleased) landed
Honor GUC settings specified in CREATE SUBSCRIPTION CONNECTION.
- f7eb44e0f087 15.16 landed
- 75f3428f2436 16.12 landed
- 7a990e801a72 17.8 landed
- 797fc5d1b38d 18.2 landed
- d926462d8190 19 (unreleased) landed
Ensure consistent logical replication of datetime and float8 values.
- f3d4019da5d0 15.0 cited

On Mon, Nov 24, 2025 at 12:52 PM Chao Li <li.evan.chao@gmail.com> wrote:
> V3 looks good to me.

Thanks for reviewing the patch!

> > Yeah, I agree that if certain GUCs can break logical replication,
> > we should enforce "safe" values, just as we currently do for datestyle.
> > And if any other GUCs can cause the issue, they could affect
> > postgres_fdw etc, so the fix would need to be broader.
>
> Just want to clarify if you mean you will handle this in a future patch?

I don't currently know of any other parameters that must be forced for
logical replication or postgres_fdw. But if we identify any, I'm happy to
review a patch that adds the necessary handling.

Regards,

-- 
Fujii Masao