Over my years as a consultant and a teacher, I have found that to be able to resolve latch and mutex contention, you must first understand Oracle's general latching and mutex algorithms, and then understand the associated specific Oracle architecture component. So, it's a two-step educational process. This chapter is devoted to the first part: understanding how Oracle serializes memory access using both latches and mutexes. This includes the general algorithms, how multiple latches are implemented, how serialization fits into Oracle's wait interface and also in Oracle response-time analysis (ORTA), and how to influence latch activity with the goal of improving response time.

Learning about Oracle serialization is full of surprises. You'll be amazed at the insight you receive, and you may enjoy recognizing that most people's latching solutions are pretty much guesswork.

If you're into speed and throughput, then serialization is death. What you want is parallelization maximization. Parallelization brings high performance, because all available resources can be used. In resolving serialization issues, our goal is to increase parallelization whenever possible, and when serialization must exist, to minimize it!