Can DBusers have other roles than db_owner?
One answer
This probably depends on the Database management system. I know that DB2 has a few instance-wide authorities and more per-database authorities.
e.g.
https://www.ibm.com/support/knowledgecenter/en/SSEPGG_9.7.0/com.ibm.db2.luw.admin.sec.doc/doc/c0005478.html
We restrict our instance authorities to the instance owner or approved users, while those ID with db authority (e.g. DBADM from the above) are the ID used to make connections to database(s) for Jazz applications.