RE: [PoC] pg_upgrade: allow to upgrade publisher node

Dear Amit,

Thank you for reviewing! New patch can be available in [1].

> + /*
> + * Note: This must be done after doing the pg_resetwal command because
> + * pg_resetwal would remove required WALs.
> + */
> + if (count_old_cluster_logical_slots())
> + {
> + start_postmaster(&new_cluster, true);
> + create_logical_replication_slots();
> + stop_postmaster(false);
> + }
> 
> Can we combine this code with the code in the function
> issue_warnings_and_set_wal_level()? That will avoid starting/stopping
> the server for creating slots.

Yeah, I can. But create_logical_replication_slots() must be done before doing
"initdb --sync-only", so they put before that.
The name is setup_new_cluster().

[1]:
https://www.postgresql.org/message-id/TYAPR01MB5866F7D8ED15BA1E8E4A2AB0F5E4A%40TYAPR01MB5866.jpnprd01.prod.outlook.com

Best Regards,
Hayato Kuroda
FUJITSU LIMITED