Fortunately for us, the wait interface will clearly tell us if the problem is latching, pinning, or locking. So while all of these may be involved, we will be able to prioritize their impact and develop appropriate solutions. During normal operations, pinning and locking are rarely a significant problem. When they are the problem, most DBAs will recognize their timing corresponds to some administrative tasks, such as altering objects, forcing recompilation, applying patching, or performing various upgrades.

I would say where most DBAs mess up shared pool latch contention is not clearly differentiating the latch situation, and therefore essentially making guesses at solutions. The library cache latch is related to finding objects in the shared pool. The shared pool latch is about memory management. Just keeping these two concepts clear will have a dramatic effect on your shared pool optimization success.

While nearly all shared pool problems are highly connected, try your best to isolate the problems and apply solutions to each of them. Our solutions become muddy and watered-down if we get sloppy and don't separate the problems. A solid understanding of the core shared pool architecture and Oracle's wait interface will allow you to do a terrific job at resolving problems.