Oracle Database 12c: RAC Administration — Question 23

Which two statements are true about the Global Enqueue Service, Instance Locks, and global enqueues in Oracle 12c RAC?

Answer options

• A. In a RAC One Node database, there is no LMD0 process if only one instance is running.
• B. Global Enqueues and Instance Locks replace mutexes completely in RAC database instances.
• C. In a RAC database, there is no LMD0 process if only one instance is running.
• D. Global Enqueues and Instance Locks replace latches completely in RAC database instances.
• E. Global Enqueues may have owners and waiters in the same instance.
• F. Global Enqueues may have converters and waiters in the same instance.

Correct answer: A, F

Explanation

The correct answers are A and F. Statement A is true because in a RAC One Node configuration, the LMD0 process is not needed when only one instance is active. Statement F is also correct as Global Enqueues can have converters and waiters within the same instance. The other statements are incorrect because Global Enqueues and Instance Locks do not completely replace mutexes or latches in RAC database instances, and statement C is misleading as it pertains to a standard RAC configuration rather than RAC One Node.