KuppingerCole analyst Rob Newby recently (August 2014) put together an executive review of the award-winning Oracle Audit Vault and Database Firewall that you can pick up here for a fee. The paper (4 pages on AVDF, 7 total) goes into a description of the solution and how it works from both the Audit Vault, and Database Firewall perspectives. It further covers reporting and alerting, as well as integration with other Oracle products, summarizing with strengths and challenges.
Happy weekend reading.