1.In the above code @vin,@dealerId are not any key they are just attributes from two different tables. Can relationship can be done using attributes instead of PK in <join> ?
2. all:dealer is a custom schema created for global market. For mexico market we have extended all:dealer with nmx namespace.When creating relationship between vehicle links and dealer tables in target which schema should I mention all:dealer or nmx:dealer ?
3 .all:dealer has autopk. In the extension schema nmx:dealer can we create a custom attribute "dealerId" as primary key. In this case what will be the impact if the table all:dealer has two primary key(autopk "id" and dealerId as custom PK) .Is it a good practice to have custom primary key for extension schema .Will this have any impact on all:dealer table