Oh man, this takes me back to 2005 when I first moved to Pg and needed replication. Its replication is statement based, i.e. sends each DML query to all nodes. That means every write query must be deterministic. That wasn't always obvious. Though it did work for us until we moved to Slony then block level WAL replication. Thankfully we have logical replication today, even if it's still a bit more painful than MySQL.

> Slony

Gosh, haven't heard that in years. I remember a company I used to work for used it on their old system but the new system didn't use it for whatever reason.