1. A method for transferring data between a first database and a second database comprising: providing a first database having a first schema with a first plurality of elements; providing a second database having a second schema with a second plurality of elements; determining the intersection elements of said first plurality of elements and said second plurality of elements which are the elements of said second plurality of elements that are common to said first plurality of elements; and transferring data that is in said intersection elements of said first database to said second database.