Description of the illustration strms041.eps

This illustration shows the following process for row migration during capture:

1. A user makes the following update to a table:

   UPDATE hr.employees SET department_id=50 WHERE employee_id=167;
   

2. The source database records the change in the redo log.

3. A capture process captures the change and transforms the UPDATE into an INSERT because the change satisfies a subset rule.

4. The capture process enqueues the transformed LCR at the source database.

5. A propagation propagates the LCR to a queue at the destination database.

6. An apply process dequeues the change and applies it as an INSERT into an hr.employees subset table. This subset table contains rows only for employees with a department_id equal to 50.