The documentation seems to imply that you can use an alternate key as a comparison but I have been unable to prove this. I added a unique index to an existing table that already has a primary key then went back into link static data. I thought there would be an option to choose between the existing pk and the newly created unique key but there wasn't a way to do it. This seems to be a very much needed feature so I hope it is implemented soon.
The documentation seems to imply that you can use an alternate key as a comparison but I have been unable to prove this. I added a unique index to an existing table that already has a primary key then went back into link static data. I thought there would be an option to choose between the existing pk and the newly created unique key but there wasn't a way to do it. This seems to be a very much needed feature so I hope it is implemented soon.