Which three statements are true about the Global Resource Directory (GRD) in Oracle 12c RAC database and in Clustered ASM? (Choose three.)
A.
All GRD Enqueue Resource master metadata is held in the shared pool of the same database instance.
B.
Clustered ASM has GRD resources distributed among all ASM instances
C.
RAC databases have GRD cache resources distributed among all the database instances and stored in the large pool of each instance.
D.
RAC databases have GRD cache resources distributed among all the database instances and stored in the shared pool of each instance.
E.
All GRD Enqueue Resource master metadata is held in the large pool of the same database instance.
F.
Shadow GRD resources may exist in more than one database instance for a resource.
G.
Only one GRD shadow resource may exist for an Enqueue Resource.
An object under global concurrency control is called a resource.
• Resource metadata is held in the Global Resource Directory (GRD).
– Global enqueue resources are used for enqueues and locks.
– Global cache resources are used for buffer cache control.
• The GRD is distributed among all active instances of each database or ASM environment.
• Each currently managed GRD resource has:
– A master metadata structure
– One or more shadow metadata structures
• The GRD uses memory from the shared pool
Wrong: C, E (GRD use shared pool not large pool)
Correct: A, D, F (B also not sure)
What does “same database” mean in A?
I pick B, D, F
not A: The resource mastering instance may be any active instance of the database or ASM environment.
Yes B: GRD is distributed among all active instances of each database or ASM environment
Yes D, not C, not E:The GRD uses memory from the shared pool
Yes F: Each instance will contain shadow resources for entities it has accessed and for which it is not the resource master.
not G: there is master and shadow resource