VSAM Management

V-ShareVSAM Data Manager

V-Share allows multiple programs to update the same VSAM file simultaneously by giving batch jobs the ability to update files within CICS.

• V-Share consists of three basic components:
  • The first component executes in the batch programs area—it intercepts the I/O requests and ships them to the second component of V-Share residing in CICS
  • The second component of V-Share resides in the CICS region owning the VSAM files—it performs all of the VSAM I/O on behalf of the batch job
  • The third component of V-Share also resides in the CICS region—it comprises a series of online programs providing the following functions:
    • Define CICS regions to use V-Share
    • Define jobs eligible to use V-Share
    • Monitor active jobs currently using V-Share
    • Suspend a job that is currently active
    • Restart a job previously suspended
    • Cancel a job
    • Reduce the rate of I/O requests being sent to CICS in the event of heavy online activity
    • Review prior executions of batch jobs
• The first and second components communicate through VTAM or through z/VSE Cross Memory Services
  • VTAM can be used when the batch job and the CICS region reside either on the same CPU or on different CPUs
  • Cross Memory Services provide a performance boost but the batch job and the CICS region must be in the same z/VSE system