Understand the server pool concepts in Oracle Real Application Clusters (Oracle RAC) environments.

• Policy-Managed Clusters and Capacity Management
  Starting with Oracle Clusterware 11g release 2, resources that Oracle Clusterware manages are contained in logical groups of servers called server pools.
• Oracle RAC Database and Server Pools
  Oracle RAC databases support two different management styles and deployment models.
• About Creating Server Pools for Oracle RAC Databases
  You can create a server pool with Oracle Database Configuration Assistant while creating an Oracle RAC database, but Oracle recommends that you create server pools before you deploy database software and databases.
• Oracle RAC One Node and Server Pools
  Oracle RAC One Node supports the use of server pools, with some limitations.