In the architecture section of the exam, expect questions that test your knowledge of very specific details about the Oracle software architecture. Specifically, you should be intimately familiar with what functions each Oracle background process performs; make sure that you know details such as what SMON does, what events cause DBWn to write dirty buffers to data files, what events cause LGWR to write the log buffer to the current online log group, which background processes perform I/O, and so on.
Understand that when a user establishes a dedicated server connection, Oracle allocates all portions of the corresponding PGA outside the shared pool. However, when a user establishes a multithreaded server (MTS) connection,Oracle allocates memory for the session’s cursor state and sort area, collectively known as the User Global Area (UGA) from the shared pool. Therefore, when you configure an Oracle instance with MTS, it is important to consider how much memory MTS sessions can allocate from the shared pool.