Real Application Cluster (RAC) Oracle 10g

Oracle 10g RAC environments support multiple instances of Oracle that access one database. An instance is where an operating system process executes, performs the work required to satisfy requests, and contains information about the requests. Each instance in the cluster usually runs on a separate server or “node,” maintains its own set of redo log files, and also maintains its own in-memory processes and in-memory storage.

For a detailed description of the RAC process, see the Replication Agent Primary Database Guide.