CICS VSAM Transparency for z/OS, Version 1.2


FBE for managing a control record

VSAM files often have a control record that is used to control update programs. The control record structure is entirely different to the structure of the remaining records in the file.

This section defines how this can be solved within CICS VT.

Definition of requirement

A control record is a technique that is often used to control integrity of updates in batch programs. For example, assume that two programs PROGA and PROGB update FILEA. The first thing each program does is to read the control record to check the status of the UPDATE-IN-PROGRESS switch.

When PROGA starts, the UPDATE-IN-PROGRESS switch is off, and therefore the file is eligible for updating. PROGA sets the switch on, updates some records but abnormally terminates. PROGB starts, but the UPDATE-IN-PROGRESS switch is on, so PROGB ends because the file is ineligible for updating.

Because the control record structure is completely different to the structure of the other records in the file, the typical solution in CICS VT is to have the control record in its own table.



Concept topic


Last updated: December 6, 2013 20:45:2

Concept Concept

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Timestamp icon Last updated: Friday, 6 December 2013


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