Chapter List

4.1 Introduction

In the previous chapter the basic database concepts of Oracle RDBMS were explored, including areas such as the instance, database, background, and foreground processes for a single instance configuration, as well as the various components of Oracle.

After the initial introduction of a single instance configuration, a RAC configuration was briefly discussed and was compared with some of the changes from its predecessor, OPS.

This chapter covers the architecture of the system, new background processes used by RAC, and new enhancements brought into RAC, such as cache fusion technology for communicating across the interconnect, cache fusion recovery, global services, and clustered database solutions. After discussing information supporting the configuration during its uptime, scenarios covering instance failures will be presented through details of how failover happens, how the resources are handled and how recovery operation is handled in this clustered database environ ment. For the readers familiar with OPS and/or RAC, this chapter will provide a review of the basic concepts and components surrounding RAC.

4.2 RAC architecture

In Chapter 2 (Hardware Concepts) the clustering options available via the various technologies (SMP, MPP, NUMA, etc.) were discussed extensively. All of these hardware architectures support applications that take advantage of these clustered solutions. One such database application is RAC.

RAC is a clustered database solution that requires a two or...