Data Replication is the process of maintaining a defined set of data in more than one location. It involves
copying changes from one database (a source) to another database (a target), and synchronizing the data in
both locations. Data Replication is a component of DB2 UDB since v5 which allows you to publish
replication sources and define replication subscriptions. These subscriptions are defined and managed using
DB2's graphical user interface administration tool known as the DB2 Control Center. The actual subscription
information is stored in Replication Control Tables which are automatically created by the DB2 Control Center the first time a replication source or target is defined.
A replication source is a table or view that you want data copied from. Before you can replicate data, you
must define a replication source to describe the information that the change-capture mechanisms will use.
When you define a replication source you must specify which columns you want to replicate. After the
replication source is defined changes to the replication source table are captured via a component of DB2
Data Replication. This component is a process that runs on the database server and is appropriately called the capture component.
A replication target is a table or view that you want data copied to. Before you can replicate data from a
replication source, you must define a subscription set that contains the replication target table. The
component of DB2 Data Replication that replicates the data from the source table to the target table is
called the Apply component. One type of replication subscription is called a Replica. A Replica, sometimes
referred to as update anywhere replication, is designed to keep multiple data sources synchronized regardless of which of the two data sources is modified.