This illustration shows three Oracle databases named mult1.example.com, mult2.example.com, and mult3.example.com. Each database has basically the same configuration:

• One queue that is used by the capture process, propagations, and apply processes.

• A capture process that captures changes in the redo log and converts relevant changes into LCRs, which it enqueues.

• One apply process that applies changes from each of the other two databases. For example, mult1.example.com has one apply process that applies changes from mult2.example.com and another apply process that applies changes from mult3.example.com. Both of these apply processes dequeue changes from the same queue.

• Each database uses two propagations to propagate locally captured LCRs to the other databases. For example, mult1.example.com has one propagation to propagate locally captured LCRs to mult2.example.com and another propagation to propagate locally captured LCRs to mult3.example.com.