Applications using VSAM RLS benefit from increased data availability inherent in a shared environment that has read/write integrity and record-level locking (as opposed to control interval (CI) locking).

However, because VSAM RLS can be used by CICS and non-CICS applications, the CICS recoverable files function provides transactional recovery for applications, VSAM RLS is expected to be used primarily by CICS applications. Transactional recovery isolates the changes made by each sharing application. CICS creates a backout log record for each change made to a recoverable file, and VSAM RLS obtains and holds a lock on each changed record. The lock remains held until the transaction ends. If a transaction fails, CICS backs out all changes made by the application to recoverable files, thus isolating the other sharing applications from the failure.

For recoverable data set, in addition to the data sharing across CICS applications, VSAM RLS enables read-with-integrity sharing by batch jobs. Batch jobs can share recoverable files while they are being modified by CICS applications. This is possible because VSAM provides the record locking and buffer coherency functions across CICS and batch. Because VSAM RLS does not provide the transactional recovery function for batch jobs, it does not allow a batch job to open a recoverable data set for output.

VSAM RLS permits read and write sharing of nonrecoverable data sets across CICS and batch jobs. Transactional recovery does not apply to nonrecoverable data sets. While VSAM RLS permits sharing, the jobs must be carefully designed to achieve correct results in a read/write data sharing environment, because they do not have the isolation provided by transactional recovery.