Suppressing a Data Capture exit routine

You can suppress the unnecessary capture of IMS database updates if those updates are made by a CCTL or ODBM address space. By suppressing unnecessary data capture, you reduce CPU usage and improve the efficiency with which data is processed in your IMS environment.

You can specify during the system definition process that a Data Capture exit routine is not called for updates that are invoked from a specific CCTL or ODBM address space. Until otherwise defined, if a Data Capture exit routine is specified on the EXIT= parameter of the DBD, the exit routine is called for all application program activity on the database, regardless of which PSB is active.

Procedure

To suppress a Data Capture exit routine from being called for database or database segment updates that are made by a CCTL or ODBM address space, specify the job name of the address space on the SUPPDCAPNAME= parameter. The SUPPDCAPNAME= parameter is in the DATABASE section of the DFSDFxxx member of the IMS PROCLIB data set.

Capture is suppressed for the database or database segment updates that are invoked by the job specified on the SUPPDCAPNAME= parameter, even if a Data Capture exit routine is specified on the EXIT= parameter of the DBD. However, if database or database segment updates are invoked by jobs other than the one that is specified on the SUPPDCAPNAME= parameter, those updates continue to be captured by the Data Capture exit routine.

If you use the SUPPDCAPNAME= parameter in an extended recovery facility (XRF) environment, the value of the SUPPDCAPNAME= parameter for the alternate IMS system can be different from the value for the active IMS system.

If updates from one CCTL or ODBM address space are to be captured and updates from another CCTL or ODBM address space are not to be captured, ensure that unique job names are used for each address space. The unique job name can then be specified on the SUPPDCAPNAME= parameter.

Do not enable this support in a replication environment if the updates made by the replication are replicated, also known as cascaded, to another system.