A very common question among new users is how wal_level works and it levels. I heard about some situations like that, a user create a new publication in its master database and he/she simply does not change wal_level to logical, sometimes, this person lost maintenance window, or a chance to restart postgres service, usually a production database, and it will discover that wal_level is not right just in subscription creation. Attempting to iterate between new (and even experienced) users with logical replication, I am sending a patch that when an PUBLICATION is created and the wal_level is different from logical prints a WARNING in console/log:
-> WARNING: `PUBLICATION` created but wal_level `is` not set to logical, you need to change it before creating any SUBSCRIPTION
Initiatives like this can make a good user experience with PostgreSQL and its own logical replication.
