The transactional services of CICS provide an ideal environment for data sharing. Exclusive locks held by VSAM RLS on the modified records cause read-with-integrity and write requests to these records by other transactions to wait. After the modifying transaction commits or rolls back, the locks are released and other transactions can access the records.

The CICS rollback (backout) function removes changes made to the recoverable data sets by a transaction. When a transaction terminates abnormally, CICS implicitly performs a rollback.

The commit and rollback functions protect an individual transaction from changes that other transactions make to a recoverable data set or other recoverable resource. This lets the transaction logic focus on the function it is providing and not have to be concerned with data recovery or cleanup in the event of problems or failures.