Since Oracle Order Management does not maintain a sub ledger like history of all changes made against a sales order, changes merely overwrite the existing data. Thus an order booked on January 31st for $500, may be modified on February 7th to reflect an increase in order value to $1,000. Unfortunately, Oracle will assign the full $1,000 to January 31st, instead of properly allocating $500 to January 31st and $500 to February 7th. Without a history of changes, it is impossible to accurately determine net bookings for a period.