Asynchronous data propagation
You can propagate captured data asynchronously as an alternative to using the data capture exit routine. You can use this option to capture database changes for selected segment types and environment information in IMS data capture log records.
This alternative is available with the addition of a logging option on the EXIT= parameter of the DBDGEN utility. You can use the logging option to capture database changes for selected segment types and environmental information in IMS data capture log records. Captured information is compressed by using z/OS® compression services to minimize the space that is needed to store the captured data on the IMS online data sets (OLDSs). After it is stored, the captured data is available for use; for example, to propagate to a Db2 for z/OS environment.
The data capture log records use the X'99' log code and have the following data capture subcodes to indicate the type of record that is being logged:
- X'04'
- Changed data
- X'28'
- End of job (EOJ)
- X'30'
- SETS call
- X'34'
- ROLS call
All data capture log records contain a common prefix, the Data Capture Log prefix, that contains the subcode that defines the type of record being logged. End of job records and SETS and ROLS call records consist entirely of this log record prefix and contain no additional information. Changed data log records, however, contain information in addition to the prefix and can span multiple physical log records to contain all of the captured data.