Frequently Asked Questions: Lock Concept - Programming

Question

What does the _SCOPE parameter mean? How does the lock owner concept work?            

Answer

Click on Lock Owners and _SCOPE-Parameter.

Question

How can I find out who is currently holding the ungranted lock? In other words, how can check the program after an ENQUEUE to determine which use is currently holding the lock so that I can let him or her know?                                  

Answer

When the ENQUEUE_... function module is returned, the name of the lock owner is listed in SY-MSGV1.

 

Question

Can I use special characters in my lock argument (especially the 'at' sign (@))?

 Answer

The 'at' symbol is used as a wildcard in SAP locks (enqueues). In other words, it can stand for any other character during collision checks. For example, the parameter value 12345@ locks the quantities 123450 to 123459, 12345a to 12345z, and 12345A to 12345Z, and all other values with any special character in the 6^th character position.               

In order to prevent the wildcard mechanism from being activated in SAP locks when it is not required, you need to ensure when enqueue function modules are called that key value parameters do not contain any wildcard characters.                                     

If key values that you want to use to lock individual entities do contain wildcard characters, you have to replace the wildcards with different characters before the enqueue is called.