Migrating to 2.1 adds extra indexes and foreign keys

I have the following data structure:

public class Foo {
    public long Id;
    public virtual ICollection<Bar> Bars { get; set; }
}

public abstract class Bar {
    // properties
}

public class Bar1 : Bar {
    public long FooId { get; set; }
    public virtual Foo Foo { get; set; }
}

public class Bar2 : Bar {
    public long FooId { get; set; }
    public long Foo Foo { get; set; }
}

// these two lines are inside the OnModelCreating method in the context
modelBuilder.Entity<Bar1>.Property(x => x.FooId).HasColumnName("FooId");
modelBuilder.Entity<Bar2>.Property(x => x.FooId).HasColumnName("FooId");

The initial migration for the code was generated using 2.0 and the Bar table had only one index and one foreign key. After making changes to the model, the first migration with 2.1 added another foreign key and index to the same property.

Is this normal, because I couldn’t find anything about this change.

[AndriySvyryd]

@dushkostanoeski You need to move the navigation Foo to the base - Bar to indicate that both derived relationships should be represented by a single FK. Otherwise you can just configure the FK name on both relationships explicitly to the same value.

[dushkostanoeski]

@AndriySvyryd I just upgraded to the 2.1.0 release, and the migration still added the extra indexes and foreign keys.