Lock Objects

Lock objects are use in SAP to avoid the inconsistancy at the time of data is being insert/change into database.

SAP Provide three type of Lock objects.

·      Read Lock(Shared Locked)

protects read access to an object. The read lock allows other transactions read access but not write access to the locked area of the table

·      Write Lock(exclusive lock)

protects write access to an object. The write lock allows other transactions neither read nor write access to the locked area of the table.

·      Enhanced write lock (exclusive lock without cumulating)

works like a write lock except that the enhanced write lock also protects from further accesses from the same transaction.

 
When you create a lock object System automatically creat two function module.
1. ENQUEUE_. to insert the object in a queue.
2. DEQUEUE_. To remove the object is being queued through above FM.