This brings us to the end of the buffer cache internals chapter. This is truly a fascinating topic, complete with interesting internal structures, latches, queues, high concurrency, in-memory objects, and ITLs! My hope is that I went deep enough into the internals to clearly explain the key Oracle buffer cache structures and their associated wait events, and then provide multiple practical solutions. I also hope I didn't go too deep and cross the border into interesting, yet not all that useful. Finally, I hope Oracle concurrency management is not such a mystery and, in your mind, fits together a whole lot better. Now it's time to turn our attention to Oracle's shared pool cache.

1 From the "Oracle TimesTen In-Memory Database" document (http://www.oracle.com/technology/products/timesten/pdf/ds/ds_timesten_imdb.pdf).

2 The database writer is more correctly called the dirty buffer writer, since it writes only dirty buffers from the buffer cache to disk. But it is nearly always referred to as the databse writer (DBWR for short). In fact, if you said "dirty buffer writer," you would get some blank stares.