As an active transformation, the Update Strategy transformation might change the number of rows passed through it. The Update Strategy transformation tests each row to see if it meets a particular condition, and then flags the row accordingly. The transformation passes rows that it flags for insert, update, or delete to the next transformation. You can configure the transformation to pass rows flagged for reject to the next transformation or to drop rows flagged for reject.

For example, you might use the Update Strategy transformation to flag all customer rows for update when the mailing address has changed. Or, you might flag all employee rows for reject for people who no longer work for the organization.