This illustration shows the details of the secondary database ps2.example.com Oracle Streams configuration, including the following mechanisms:

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

• A capture process that captures changes in the redo log and converts relevant changes into LCRs, which it enqueues. The capture process captures a change only if its tag is NULL.

• One propagation that propagates captured changes to ps1.example.com.

• One apply process that applies changes from ps1.example.com. These changes have a tag of '00' in the redo log.