So for pg upgrade in streaming replication setup, rsync will be a better option for standby upgrade if we are using --link option or recreating the standby, once upgrade completes on primary? Any suggestions on this please.
We are in the process of upgrading our PostgreSQL database from version 12 to version 15. I would greatly appreciate your advice on the following:
1. Would it be recommended to use the --link option with the pg_upgrade command, from disk space point of view?
Yes.
Are there any potential downsides to consider?
Very much: it's a one-way journey. No rolling back if something goes wrong!
2. Do you have any suggestions or best practices for performing an efficient upgrade in a replication setup (streaming replication) for both the primary and standby servers?
Streaming replication is not an upgrade method. Logical replication is absolutely a valid method of upgrading PG on one server to PG on a different server.
