This illustration shows the following process for row migration during apply:
A user makes the following update to a table:
UPDATE hr.employees SET department_id=50 WHERE employee_id=145;
The source database records the change in the redo log.
A capture process captures the change and enqueues it as an LCR at the source database.
The propagation propagates the LCR to a queue at the destination database.
An apply process dequeues the LCR at the destination database and transforms the UPDATE
into an INSERT
because the change satisfies a subset rule.
The apply process applies the change as an INSERT
into an hr.employees
subset table. This subset table contains rows only for employees with a department_id
equal to 50
.