In Oracle the needed certifications are hard. These last years due to many tools the Oracle Database Admin the most the cases is an Oracle Database Operator. Maybe hard is the tuning. But you are going to need to work nights, weekends and you must have a clear brain, to be accurate and fast, because 1 hour without a DB is a big cost for a big company.
70.0%United States of America (the)
14.6%Russian Federation (the)
10.2%China