TAW_11 Chapter 7, SAP Locking Flashcards
How many application servers have enqueue processes?
Just one. And SAP recommends a central lock server
What do customer lock objects start with
EY or EZ
What would the lock FMs for lock object EZMYTAB be?
ENQUEUE_EZMYTAB, DEQUEUE_EZMYTAB
What can a loc module do?
Set a lock
Promote an optimistic lock
Check if a lock can be set or promoted
Do I need to DEQUEUE all ENQUEUE objects at the end of a process?
You can dequeue one by one, or do FM DEQUEUE_ALL but most people don’t dequeue at all because SAP will automatically release the locks at the end of the process
Lock objects are passed as part of the update process?
True if the scope is 2 or 3
If WAIT is specified, the enqueue keeps trying until the lock is available?
False, ith number of retries is a system configuration. The defaults 5
what is the _collect parameter
Collect all locks in a container and then process all equeue together
What are the two shared lock modes?
S to set the lock
W to see if the lock can be set
Optimistic lock mode is
O
Cumulative lock mode are
E for set
V to see if the lock cn be set
Non-cumulative lock modes are
X for set
U to see if it can be set
Modes to promote optimistic locks are
R to set
C to see if it can be set
What is the default _scope?
2, the lock is sent to the update process which then can delete the lock
What is _scope 3
Two locks are set, one managed by the program, and one sent to the update
What is _scope 1
The lock is managed by the program. This is used for inline updates that do not have update tasks
What transactions allow the viewing and terminating of locks
SM12
How are collected locks sent to the system
FLUSH_ENQUEUE sends all locks from the lock container and gives a single return code.
You should use FM RESET_ENQUEUE to clear the lock container
