while DBA is the one who sets up sysadm, he shouldn't be PeopleSoft administrator. In the best of the worlds you have Unix admin ('root'), NT admin ('Administrator'), DBA ('oracle'), and PeopleSoft admin ('VP1' and 'sysadm'). These are different roles, requiring different skills, and to assume that DBA will administer PeopleSoft is a very risky path. And just like you have a DBA team (3-4 people, on-call, etc.), you would want to have at least 3 people in PeopleSoft administration team.
Then, of course, reality strikes and you have one DBA that is also PeopleSoft admin who is on call 24/7 and whose cell goes off the hook every time a process schedule goes down