Before you can install and configure Oracle Parallel Server (OPS) successfully, you need to understand its various architectural components. If you are new to OPS, this chapter is definitely for you. If you are familiar with OPS concepts, this chapter will serve as a review of the OPS features and components before you move on to the details in subsequent chapters. This chapter introduces Oracle Parallel Server and discusses the OPS features related to instance and database architecture. It also describes how datafiles, the Integrated Distributed Lock Manager (IDLM), and rollback segments work with OPS.
Remember that parallel execution and Oracle Parallel Server are two separate feature sets available from Oracle. They are independent of each other but can work together. Most OPS environments also run parallel execution. Parallel server adds some additional features to parallel execution. Chapter 13, explains how you can exploit parallel execution features in an Oracle Parallel Server environment.
For simplicity, most of the diagrams in this chapter use a two-instance OPS environment to illustrate the concepts being described. However, remember that the discussions here are applicable to OPS with any number of instances.
One of the key differences between an OPS database and a standalone Oracle database is that with OPS, you have multiple instances opening the database at the same time. This is a crucial point ...