With Oracle RAC databases, you can adjust the number of instances and which nodes run instances for a given database, based on workload requirements. Features such as cluster-managed services allow you to manage multiple workloads on a single database or across multiple databases.
It is important to properly manage the capacity in the cluster when adding work. The processes that manage the cluster—including processes both from Oracle Clusterware and the database—must be able to obtain CPU resources in a timely fashion and must be given higher priority in the system. Oracle Database Quality of Service Management (Oracle Database QoS Management) can assist consolidating multiple applications in a cluster or database by dynamically allocating CPU resources to meet performance objectives. You can also use cluster configuration policies to manage resources at the cluster level.
See Also:
Oracle Database Quality of Service Management User's Guide for more information