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: Amit Kapila <amit.kapila16@gmail.com>

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

Date: 2025-12-02T14:59:55Z

Lists: pgsql-hackers

Commits

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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 Tue, Dec 2, 2025 at 9:08 PM Amit Kapila <amit.kapila16@gmail.com> wrote:
> Is it possible that we append the predefined options to the options
> given by the user to avoid extra round-trip?

One idea is to add a function, similar to libpqrcv_get_dbname_from_conninfo()
in libpqwalreceiver.c, that extracts the options string from the conninfo,
to append the required fixed settings, and then to use the combined string as
the value of the options parameter. Do you think implementing this is worthwhile
to avoid the extra round trip?

Regards,

-- 
Fujii Masao