I understand the linking of key fields from one database to another. The “Relational Database Management” help file uses an example of people’s names. For my contacts database this seems great except that I have on occassion needed to deal with people with the same first and last names. I could instead use the PersonID value, but this is letters and numbers and means that for every person I have to constantly look up the PersonID value.
I can’t say what the “best” solution is for your application. I can only say that by definition, key values have to be unique. The whole point of a key value is that it uniquely links a record in one database to a record in another database.