Can we define a composite primary key in Eloqua?

Product name: Eloqua

Now a days in our Eloqua system the primary key is the clients’s email, but at the moment there are many duplicated data, for that reason we are thinking in a composite primary key by the email and the document id of our clients, the objective of this post is verify if Eloqua can use a composite primary key or there are another solutions from oracle for this kind of situation.