The Change Selector is a process, a Connect CDC executable, that identifies data that has changed during replication and stores this data in a change queue until it is distributed to the target tables. The changed data includes SQL row operation changes, specifically INSERT, UPDATE, and DELETE in the context of an SQL transaction.
The IBM i Installation Guide specifies how to install the Change Selector on IBM i. The DB2 Change Selector is used for replication on DB2 servers only and differs from the Oracle Change Selector, described in Oracle change selector. A Change Selector for UDB DB2 models is automatically added during installation.
Note the following when using UDB:
You must set up UDB with archive logging, not circular logging.
Tables must have data change capture enabled.
Bringing the database down always forces the Change Selector to stop.