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Capture New IMS Data |
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Whether initiating Change Data Capture for the first time, expanding the original selection of data or including a new source of data from the implementation of a new application, the steps are very similar. The impact on new or existing Capture and Apply processes can be determined once the source of the data is known, precisely what data is required from the Source, whether business rules require filters or data transformations and where the Target of the captured data will reside.
Example:
Our example starts with the addition of a new Segment to an existing IMS Database DBD.
Solution:
In order to capture the changes for IMS database segments, the EXIT keyword must be specified on either the SEGM or DBD keywords in the IMS Database Descriptor (DBD). Generally when a new segment is added to an existing IMS database, the method for specifying capture will be the same as previously used for existing segments.
After examining the DBD, review the current XPARM configuration. While the default is Segment level Routing in the Object Destination Section, most often a wild card is used after the DBD_name in the object1 |*.object2 |* = [target] specification.
-- ---------------------------------
-- OBJECT DESTINATION SECTION
-- ---------------------------------
UOWROUTE=N
ROUTE=SEGMENT
IVPDB1.*=SQDATA.IMSCDC.LOG1
In this case the XPARM will not require any changes.
Finally, determine how the new data will affect existing Engines and modify the Engine script accordingly. See the Engine Reference for all the options available through Engine Script commands and functions.
Notes:
1.If the XPARM was updated and a new LogStream was added to accommodate the captured data, the LPARM or Resolve In-Doubt Log List parameter must be updated to ensure that it contains the full list of LogStreams. See the section Configure and Generate Resolve In-Doubt (LPARM) Log List.
2.Whenever a new source is to be captured for the first time, consideration must be given to the existing state of the source datastore when capture is first initiated. The most common situation is that the source already contains data that would have qualified to be captured and applied to the target, if the CDC and Apply process had already been in place. A variety of methods are available to perform both Initial Target Load and Refresh.
