14 This maximum value will certainingly change from one Oracle version to the next, so don't look at this number as a fixed maximum, but more of an indication of how much memory Oracle may want to keep specifically for ASH buffers.

15 There is a kind of double hit in this situation. Because many hardware and software licenses are based on the number of CPU cores, the more CPU consumed by performance software, the more any CPU-related license will cost. So the cost of CPU consumption is not just the simple CPU time consumption calculation, but is also related to the cost of software licenses.

Oracle's buffer cache is a fascinating topic. It has everything you need for a fantastically horrific yet exciting performance nightmare: high concurrency, latches, locks, queues, lists, nodes, in-memory objects, and more. Add in a few irate users, and you'll have stories to tell you grandkids. With so many algorithms and pieces of kernel code simultaneously in operation, contention opportunities abound. Fortunately for us, an analysis focused on response time can detect specifically where the contention resides and, when combined with a solid understanding of the related internals, a number of possible solutions will result.