Summary
In this chapter, we looked in detail at the DB2 database layer. We described the 15 Q Capture control tables, the 14 Q Apply control tables and the 12 Replication Alert Monitor control tables. We looked at where these control tables go, how they are pruned, and unveiled queries which can be run against the control tables to extract information about the current state of the Q replication set up. Finally, we looked at communicating with Q Capture using the IBMQREP_SIGNAL
control table, and why it is important to restrict access to this table, to stop unauthorized users from compromising the Q replication environment.
We will now go on to look at the second component of a Q replication solution, namely the WebSphere MQ layer.