I have noticed a strange behaviour regarding WAL sequence numbers. I am populating a new DB with old data. To populate the largest part of the data I use wal_level=minimal and archive_mode=off. Then I stop the database and set wal_level=hotstandby and archive_mode=on. After I do that, I notice that the WAL sequence number "rewinds" a little bit, overlaping with the old ones... Is this normal?