Re: Have pg_basebackup write "dbname" in "primary_conninfo"?

On Tue, 20 Feb 2024 at 00:34, Ian Lawrence Barwick <barwick@gmail.com> wrote:
> With the addition of "pg_sync_replication_slots()", there is now a use-case for
> including "dbname" in "primary_conninfo" and the docs have changed from
> stating [1]:
>
>   Do not specify a database name in the primary_conninfo string.
>
> to [2]:
>
>   For replication slot synchronization (see Section 48.2.3), it is also
>   necessary to specify a valid dbname in the primary_conninfo string. This will
>   only be used for slot synchronization. It is ignored for streaming.
>
> [1] https://www.postgresql.org/docs/16/runtime-config-replication.html#RUNTIME-CONFIG-REPLICATION-STANDBY
> [2] https://www.postgresql.org/docs/devel/runtime-config-replication.html#RUNTIME-CONFIG-REPLICATION-STANDBY

Sounds like that documentation should be updated in the same way as
was done for pg_basebackup/pg_receivewal in commit cca97ce6a665. When
considering middleware/proxies having dbname in there can be useful
even for older PG versions.

> I can't see any reason for continuing to omit "dbname", so suggest it should
> only continue to be omitted for 16 and earlier; see attached patch.

Yeah, that seems like a good change. Though, I'm wondering if the
version check is actually necessary.