Do we need primary key on table referencing two other table?
I have a table having columns ProductTypeID, BrandID, SupportedBatteryID, which stores batteryIDs supported by a particular product.
Non of the columns here are unique, So do i need a primary key on these kind of tables?
If i will add a primary key will it increase the performance while searching batteries for a particular product by using product id?
You can build a clustered index on (ProductId, SupportedBatteryId). This will help you without creating a Primary key