PowerExchange reads change data from the DB2 journal receivers for the database that contains the source tables. For CDC to work, source tables must configured to use journaling.

If you configure PowerExchange Condense, PowerExchange Condense captures change data from the DB2 journal receivers and writes that data to condense files. The change data is then extracted from the condense files. Benefits of using PowerExchange Condense include faster restart of change data capture and no prolonged retention of journal receivers.

With either CDC strategy, you must define a capture registration for each source table. In the capture registration, you can select a subset of columns for which to capture data. PowerExchange generates a corresponding extraction map.

If a source table contains columns in which you store data that is inconsistent with the column datatype, you can create a data map to manipulate that data with expressions. For example, if you store packed data in a CHAR column, you can create a data map to manipulate that data to prepare it for loading to a target. Then, you merge the data map with an extraction map.

PowerExchange works in conjunction with PowerCenter to extract change data and load it to one or more targets. In PowerCenter, you must create a mapping, workflow, session, and connection. When you are ready to replicate change data, you just verify that the capture registration is active and start the workflow.