Explanation/Reference:
Explanation:
A resource consumer group (consumer group) is a collection of user sessions that are grouped together based on their processing needs. When a session is created, it is automatically mapped to a consumer group based on mapping rules that you set up. As a database administrator (DBA), you can manually switch a session to a different consumer group.
Before you enable the Resource Manager, you must specify how user sessions are assigned to resource consumer groups. You do this by creating mapping rules that enable the Resource Manager to automatically assign each session to a consumer group upon session startup, based upon session attributes.
Oracle Database Resource Manager (the Resource Manager) enables you to manage multiple workloads within a database that are contending for system and database resources.
In addition, the Database Resource Manager can map services to consumer groups. Therefore, you can automatically manage the priority of one service relative to others. You can use consumer groups to define relative priority in terms of either ratios or resource consumption.
Oracle Database Administrator's Guide