The plan is the top of a hierarchy of plan directives and consumer groups. It is also possible to create subplans. Only one plan can be in effect at one time, but you can define multiple plans in one database and switch between the plans.
||Each plan directive contains resource limitation settings. The settings define CPU levels and usage within levels and session parallelism.
|| A database can have many consumer groups. Each one has a name and is intended to be a group of users with common resource consumption needs. You assign a plan directive to each consumer group, thus limiting the group's resources.
||A user can be assigned to one consumer group at a time. When the user is not explicitly assigned to a consumer group, the user is assigned to a default consumer group.
||A user's sessions belong to the user, and therefore all the restrictions of the user's consumer group apply to all the user's sessions.