Oracle RAC DBA Course Introduction

Overview of Oracle RAC Database Administration

Oracle RAC databases support two different management styles and deployment models:

Administrator-managed deployment is based on the Oracle RAC deployment types that existed before Oracle Database 11g release 2 (11.2) and requires that you statically configure each database instance to run on a specific node in the cluster, and that you configure database services to run on specific instances belonging to a certain database using the preferred and available designation.

Policy-managed deployment is based on server pools, where database services run within a server pool as singleton or uniform across all of the servers in the server pool. Databases are deployed in one or more server pools and the size of the server pools determine the number of database instances in the deployment.

You can manage databases with either the administrator-managed or policy-managed deployment model using the same commands or methods (such as DBCA or Oracle Enterprise Manager). All commands and utilities maintain backward compatibility to support the management of Oracle databases that only support administrator-based management (Oracle databases before Oracle Database 11g release).

In general, a database is defined as a resource in Oracle Clusterware. The database resource is automatically created when you create your database with DBCA, or you can manually create the database resource by adding your database with SRVCTL. The database resource contains the Oracle home, the SPFILE, one or more server pools, and one or more Oracle ASM disk groups required for the database. The database resource also has a weak start dependency on the listener type, which means that the resource tries to start all listeners for the node when the database instance starts. Oracle Clusterware tries to start listeners on the node where the database instance starts. Starting the listeners in turn starts the VIP for the node.