If you add or drop columns in a Db2 for z/OS source table, you must create a new capture registration. PowerExchange generates an associated extraction map by default. Use the generated extraction map instead of creating a user-defined extraction map. The PWX CDC Reader on the Db2 for z/OS CDC Connector system will retrieve information from the new generated extraction map.
To switch to the new table definition and preserve access to previously captured data, you must perform several steps in both the PowerExchange and Db2 for z/OS CDC Connector environments.
Note: You do not need to perform these steps if you selectively capture change data for a subset of columns, and the DDL changes do not affect any of these columns.
1Stop data change activity on the Db2 source table on the z/OS system.
2Verify that the Db2 change capture routine (Db2 ECCR) has captured all change records up to the point at which change activity was stopped.
3Verify that the change records that were captured under the current table definition have been extracted by Db2 for z/OS CDC Connector and written to the target. Then stop all mapping tasks that extract change data for the table.
4Shut down the PowerExchange Logger for Linux, UNIX, and Windows.
5In the PowerExchange Navigator, open the original capture registration and set its status to History.
6Add or drop columns in the source table.
7In the PowerExchange Navigator, create a new capture registration for the table that reflects the column changes. Include the following settings:
- In the Condense list, select Part.
- In the Status list, select Active.
8Issue the Db2 ECCR REFRESH command so that the PowerExchange change capture routine can use the new registration.
9Warm start the PowerExchange Logger for Linux, UNIX, and Windows.
10Alter the target table to reflect the source table changes, if necessary.
11In Data Integration, for each mapping that includes the source table, perform the following steps:
- Select the Source transformation. Under Source Properties, either click the Synchronize button on the Fields tab or select the table again in the Object field on the Source tab. Either action causes the PWX CDC Metadata Adapter to retrieve the updated extraction-map metadata.
- If you changed the target table, select the Target transformation. Under Target Properties, click the Synchronize button on the Target Fields tab or select the table again in the Object field on the Target tab.
- Edit the field mapping to reflect the added or removed columns.
12If necessary, rematerialize the target tables.
13In the mapping task, set a time-based restart point that coincides with the time of target rematerialization or let the mapping task restart from the last checkpoint that was recorded in the state table on the target.
14Allow change activity to resume on the source table.