Database Resource Manager (DRM) provides the resource
management facilities. In a database instance, which is highly
active and concurrently accessed by large numbers of users,
control of suitable resource allocation is essential. In the
absence of a better resource control, some critical and high
priority sessions or tasks may not get required resources in time.
Oracle DRM is a framework that provides a mechanism to control the
resource allocation.
The DRM helps to allocate a percentage of CPU time to different
users, user groups, and applications. It can limit the parallelism
of any operation by allowing other competing processes to get
their share of resources. It also can create resource pools, such
as the ‘undo pool’ and the ‘active session pool’, that help
control the execution resource availability for a group of
sessions.
Oracle10g Components of DRM
There are three main components with which you can define and
manage resource allocation. They are:
Resource Consumer Group – These are the named entities,
which are groups of users or sessions combined together, based
on their processing and resource needs.
Resource Plan - Contains the directives that specify how the
resources are allocated to the resource consumer groups.
Resource Plan Directive – These are used to associate
resource consumer groups with particular resource plans and
allocate resources among the resource consumer groups.
The Oracle package dbms_resource_manager is used to create and
maintain the resource plans and manage the resource consumer
groups.
