Oracle Database Administration 2019 Certified Professional — Question 6

Which two statements are true about the Global Enqueue Service, Instance Locks, and global enqueues in Oracle 19c RAC? (Choose two.)

Answer options

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

Correct answer: C, E

Explanation

The correct answer is C and E because in Oracle 19c RAC, global enqueues can indeed have owners and waiters in the same instance, and when only one instance is running, no LMD0 process is present. Options A and D are incorrect as mutexes and latches are not completely replaced by Global Enqueues and Instance Locks, while B is wrong since converters and waiters can be in different instances.