Tuning differences: single instance versus RAC
Many DBAs are confused about how to approach performance tuning for Oracle RAC environments in contrast to single instance databases. By understanding the system architecture differences, as well as how Cache Fusion affects an RAC environment, you will be prepared to tune Oracle RAC. Cache Fusion brings new challenges and performance optimizations unique to RAC as opposed to single instance Oracle database environments, which we will examine later in this chapter.
Oracle 11g single instance database
Single instance database environments for Oracle are simpler to tune than RAC environments for the simple reason that you do not have to worry about tuning issues with respect to interconnect cluster communication. We believe that an holistic view is paramount when tuning RAC environments for Oracle. After you have tuned SQL, as well as sized the database correctly, you should address the unique characteristics for an RAC environment.
