Oracle 12c does not eliminate the need for daily administrative tasks of a database administrator, however it does have many enhancement that can aid in the identification of problems/sub-par performance.    Additionally, there exist two camps on monitoring the health of a database:  One wanting to automate all monitoring tasks and let the database tell you when something is wrong; and One that wants tasks to remain manual where you keep a closer contact with database structures and are able to determine trends.  Regardless of how you perform your monitoring, the following list of daily DBA tasks is a good general guideline.   NOTE:   This list is not limited to just error checking, a DBA job covers both error correction and error avoidance.

1. Check for any database errors in alert and trace.
2. Check for any networking errors in listener alert. (other network connectivity logs)
3. Check for errors in Operating System log files for database servers.
4. Check for errors in Storage Area Network log files.
5. Check Space allocation for database storage. (database tablespaces)
6. Check for Space availability at Operating System Layer.
7. Check any Application Layer error logs.
8. Installing, Upgrading, and Patching Oracle Database server software (OS) and application tools. (Test installing, upgrading, and Patching before production implementations)
9. Allocation of system storage and planning future storage.
10. Creating primary database storage structure (tablespaces)
11. Create primary database objects (tables, views, indexes)
12. Planning backup and recovery procedure.
13. Consult oracle technical support
14. Ensure compliance with Oracle license agreement.
15. Modify database structures.
16. Managing users and maintain security.
17. Controlling and Monitoring user activity and privileges.
18. Monitor and optimize performance.
19. Maintain archive tape backup/recovery devices (other type of backup device).
20. Backup and restore database. (including test recovery at least twice a year)

Larry Catt

OCP