SQL Locks 
In the Problem Analysis user menu, you can, among other things, display all active and requested locks.
Exclusive locks mean that other users cannot access the locked entry. These locks can significantly interfere with the performance of the SAP system and the database system.
Procedure
Open the Database Assistant (transaction code DB50) or the liveCache Assistant (transaction code LC10). Choose 
Problem Analysis 
SQL Locks 
.
Result
The following views are available:
Determining the User Who Triggered a Lock
In a database belonging to an SAP system, the name of a standard user could be SAPR3. You can use the Task Manager to find the task ID (ID) and the corresponding application PID and application server.
Then use the Process Overview (transaction code SM50) or the Application Server Overview (transaction code SM51) to find out which SAP work process triggered the lock request or lock.