Database Reference
In-Depth Information
Figures 7-6.
Creating and managing server pools within Oracle Enterprise Manager Cloud Control
Planning and Designing RAC Databases
Before a new RAC database is deployed in a complex/large-scale cluster environment, it is essential that you carefully
plan and design the database resources keeping in view the requirements from the application and business points
of view. When you plan a new database, you have to consider the core requirements of the application and future
business demands, such as increased workload, how to control the resources on the server, etc. When multiple
databases are configured on a node, each database has a different requirement for CPU and memory resources.
Some databases need more resources, while others need much less. However, there will be no control over the CPU
consumption by default to the instances running on the node.
In the subsequent sections, we give you some valuable tips to optimize RAC databases by introducing some
of the new features introduced in the recent and current Oracle versions, for example, instance caging and
policy-managed database.
Policy-Managed Databases
From 11gR2 onward, you will be given a choice to create two alternative types of RAC database management
configuration options during database creation within DBCA:
admin managed
and
policy managed
. Depending on the
application and business needs and considering the business workload demands, you can choose the configuration
option to create either an
admin-managed
or a
policy-managed
database. The typical admin-managed databases are
sort of static and assign to a specific set of nodes in the cluster, their connect configuration as well. You will define
your requirements during the course of database or its service creation, which is pinned to particular nodes on which
they will be deployed and reside in. Whereas, a policy-based database, on the other hand, is more dynamic in nature
and thus will act according to workload requirements. For a policy-managed database, resources are allocated in
advance, keeping future requirements in mind, and can be adjusted just-in-time dynamically without much change to
the connection configuration.
It is a common factor in a large-scale production RAC setup with a huge number of databases deployed that
each database's requirements and use are quite different from those of the other databases in nature. In contrast to a
traditional admin-managed database, a policy-managed database has the ability to define the number of instances
