I have a question about the operation and flow of records. Let's make the following change to your data.. Let's assume that the data coming in was using a super key (FirstName, LastName, Email). Then we write the data using only the PK E-Mail, but we grab all the records.
(Lets asume we had the following data already there.. Tim, Jones, email@example.com. : Now the data coming in.. (Tim, Jones, Timj@aol.com), (Tim, Jones, Jonest@aol.dom), (Tim, Jones, firstname.lastname@example.org)
I think the operation would be.. All records would go to the matching and then email@example.com would be dropped, since it matches. The others would update the existing record, so only the last write would exist in the database.
My test seems to prove this... just want to make sure my logic is correct.