Lock Management (Enqueue)

What are the four SAP lock modes?

What path does a lock request travel before a lock is granted or rejected?

How does a standalone enqueue server provide high availability?

How do you recognize the instance that runs the enqueue (lock) service?

What is the difference between a lock object and a lock entry in AS ABAP?

Which parameters configure the lock table and enqueue service?

What does the _SCOPE parameter on the ENQUEUE call control, and what do its values mean?

In transaction SM12, what is the difference between blue and black lock entries?

Where does the lock table physically live, and what is reloaded when the lock server restarts?

In current SAP systems, which transaction monitors the lock table alongside the classic SM12?

What advantages did the standalone enqueue server (Kernel 6.40+) introduce, and what does it require of its instance?

Why is an ENQ work process not strictly required on a pure central instance, yet still recommended?

What does Peak Util mean in SM12 lock statistics, and what causes lock-table overflow?

How does the lifetime of an SAP lock compare to a database lock, and how does it survive an enqueue server failure?