When I was being taught Oracle 9i(OCP) our Instructor made the point that if buffer cache hit ratio should be at the acceptable level of 95%, and if it fell below 95% to add more ram(tuning). All but 1 article that I have read on the subject, and outside books(2) that I have said the same thing, "when buffer cache hit ratio falls below 95% throw more ram(tuning) at it until it rises back up to 95%.

I truely understand that some of you strongly suggest that we(newbies) RTM, but when we read the manual, and it says the same thing, I feel that I have been cornered into asking you folks for assistance.

As mentioned earlier in this post (All but 1 article that I have read on the subject) it only touched on design, it did not get real in depth about it.

I throw in with JMac on this one, what should a DBA tasked with buffer cache hit ratio look for in this matter?

Rick