You can run PowerExchange on the remote system where the remote journal receivers reside and not on the local system where the source tables reside. PowerExchange can use distributed data management (DDM) to access metadata for the DB2 source tables on the local system for registration and database row tests, provided that you specify values other than the default values for the RMTRDBDIRE and RMTSYSNAME parameters in the CRTPWXENV command or DBMOVER configuration member.

If you have copies of the DB2 source tables on the remote system, PowerExchange can access metadata for the tables without using DDM. In this case, you must accept the default values for the RMTRDBDIRE and RTMSYSNAME parameters. Also, PowerExchange does not create

dtllib

and

datalib

libraries on the local system during installation.

You might want to use remote journals for change capture if your local production system has space constraints or high overhead. By running PowerExchange CDC processing on a remote system with higher availability, you can avoid degrading performance of the production system.

The following figure shows a simple PowerExchange CDC configuration in which PowerExchange reads change entries from remote journal receivers and the source tables reside only on the local system:

In this configuration, the local i5/OS system contains the following items:

The remote system contains the following items:

When an application updates a journaled DB2 source table on the local system, i5/OS writes the entries for the changes to the local journals. Each local journal is associated with at least one remote journal. i5/OS replicates journal entries from the local journals to the associated remote journals. PowerExchange gets the journal entries from the remote journal receivers for the source tables and columns of interest, as identified by the capture registrations. If you use PowerExchange Condense, PowerExchange Condense reads the changes from the remote journal receivers and writes the changes to condense files on the remote system.

When you register DB2 source tables or perform database row tests from the PowerExchange Navigator, the PowerExchange Listener on the remote system connects to the local system to read metadata for the source tables. The PowerExchange Listener uses the SQL package and views in the

dtllib

and

datalib

libraries on the local system to access the metadata. PowerExchange stores the capture registrations and corresponding extraction maps in the

datalib

and

cpxlib

libraries, respectively, on the remote system.