Nope. FDMEE needs to stage the data so it can perform mapping and other transformation logic on it.
You can also use the Universal Data Adapter (UDA) to connect to a database view. Maybe create a view that does some of the data manipulation for you to resolve the duplicate records issue.
ThinkFDM is correct.
If you are already using your Universal Data Adapter, you might want to consider to aggregate the transaction data in your Oracle Database to make the data faster.
when I setup the ODI for FDMEE, I refer to tuning guide: http://www.oracle.com/technetwork/middleware/bi-foundation/fdmee-tuning-1112x-2349440.pdf
But it does not really improve my customer data upload(especially in December :where they upload January - December data to be put in December amount in HFM).