The following documentation comment has been logged on the website: Page: https://www.postgresql.org/docs/16/runtime-config-custom.html Description:
As far as I can tell, the following statement: > PostgreSQL will accept a setting for any two-part parameter name does not hold when creating a *new* setting with `ALTER SYSTEM`, e.g. ALTER SYSTEM SET foo.bar TO 'baz'; will elicit an error. However, if `foo.bar` is defined in `postgresql.conf` or `postgresql.auto.conf` – put there by hand – then it can be altered, i.e. the `ALTER SYSTEM` command above will succeed. I don't know if this is something that should be mentioned in the documentation or if it's an inconsistency in the implementation.
