Anybody have any measure/unitary test about reading/comparing versus just writing always? Let me try to elaborate: Custom transaction column which you update from another column on creation or edit. You have two scenarios: Scenario 1: 1 - Read source field 2 - Read destination field 3 - Compare 4 - Write if Needed Scenario 2: 1- Read Source field 2- Write to Destination Field. My question is which one is more efficient?