In relational databases we can only define one primary key. Is it possible to define two primary keys, probably one is primary and other is secondary key and can be joined on any of the two fields.
Could you tell a bit more about your goal? That might help to give you the best answer. More than one road leads to Rome after all. :-)
You could have
unique indexes set up by Salesforce, but these may require Salesforce Services (at a fee), although you can also try to initiate a support ticket. I'm not sure if they would handle that now.
Another - perhaps easier - work around is to work with two data extensions:
- DE1: Primary key + any other information
- DE2: Primary key (as a look up to DE1) + your "secondary key"
Then you could write a (SQL) Query Activity. Something like:
SELECT field1 field2 ... FROM DE1 INNER JOIN DE2 DE1.PrimaryKey on DE2.PrimaryKey
Or use a third party tool like DESelect if you don't like writing SQL.
Let me know if this helps! :-)