Forward Mapping DB Layout

Hi,
Suppose I have an M:N relationship between Item1 and Item2, each with an ID property of type GUID.  Using the forward mapping wizard will generate:

Key - Item1ID - GUID
Key - seq - int
Item2ID - GUID

Since this is an M:N relationship, I would like to have it as:
Key - Item1ID
Key - Item2ID
 and then a sequence or timestamp or version stamp.

Is this possible?  What is the advantage to doing it the first way?  If you know you are going to be looking up info from both sides of the M:N, then why not index them both?

Hello David ,
 
 The advantage of having the sequence is that the order of instances in the collection is maintained. You can uncheck the 'Preserve order' checkbox on the collection field mapping and OA will create a PK on the 2 ID columns.

Regards,
the Telerik team