I’m now a certified expert in Oracle. Just cleared the 1z0-048 exam for Oracle RAC 10g Cluster. The exam tests you on RAC Administration and Cluster Managment. It consists of 2 sections and you need to clear both sections to pass the exam. It tests you with some real world scenarios working in a RAC environment. It was quite challenging. The preparation material from Oracle is very helpful. But you need core experience working on RAC to successfully clear this exam.