Ora

Discuss in 700 words or more on AUDIT_ADMIN and AUDIT_VIEWER and why are they introduced by Oracle 12c. Include a discussion of what database auditing is and what it does. Consider why these new roles were introduced and what problem they are meant to resolve. Do not simply define the roles. Explain why they are useful. 

Cite your sources in-line and at the end. Provide a URL for your citations.