Within a resource-plan definition, what differentiates a top-level plan from a subplan?
A.
A subplan has the PLAN_SUB parameter value set to SUB.
B.
A top-level plan has the GROUP_OR_PLAN parameter set to the name of the subplan in the
resource-plan definition.
C.
There is no difference in the resource-plan definition.
D.
A subplan always has the CPU_MTH parameter value set to RATIO.
E.
The string TOP_LEVEL is appended to the name of top-level resource plans.
About Subplans
Instead of referencing a consumer group, a resource plan directive (directive) can reference another resource plan. In this case, the plan is referred to as a subplan. The subplan itself has directives that allocate resources to consumer groups and other subplans. The resource allocation scheme then works like this: The top resource plan (the currently active plan) divides resources among consumer groups and subplans. Each subplan allocates its portion of the total resource allocation among its consumer groups and subplans. You can create hierarchical plans with any number of subplans.
You create a resource subplan in the same way that you create a resource plan. To create a plan that is to be used only as a subplan, you use the SUB_PLAN argument in the package procedure DBMS_RESOURCE_MANAGER.CREATE_PLAN.
In any top level plan, you can reference a subplan only once. A subplan is not required to have a directive to OTHER_GROUPS and cannot be set as a resource plan.