Real Time Database Monitoring Products

Any one on the list used Sentrigo hedgehog http://www.sentrigo.com/ NI light of the fidelity incident our compnay is evaluating solutions for real time monitoring and i was wondering if anyone has any experience with this product . Also i know Oracle Database Audit vault is out there but any other products that i should look at . anyone implement such solutions. What the performance overhead and issues etc.

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