The DB2 ECCR connects to the subsystem with the SSID that is specified in the CN statement of the REPL2OPT DD data set, or in the RN statement if the CN statement is not specified. This single DB2 ECCR performs the following processing:

If you create a single data sharing group that includes existing DB2 subsystems and you want to continue to use their existing capture registrations, you must run multiple DB2 ECCRs. Run one ECCR for each subsystem from which you capture changes. Each subsystem SSID must be specified in a RN statement in the REPL2OPT DD data set.

After successfully migrating to a data sharing environment, you can minimize the number of ECCRs by combining those that are on members in the data sharing group. However, you must then register all of the DB2 tables from which the ECCRs capture changes under a common SSID or group attachment name. You also might need to change your extraction mappings and processes.