When new features are added, the designer can understand whether they will lead to database redesign. As an example, in a multimedia relation R = {photo, name, address}, where the mfd: photo_g1(t1) -> {name, address}_g2(t2) holds, suppose that photo can be in turn characterized by independent features such as eye, nose and mouth. In other words, three new features are selected. This can be incorporated into database design as follows. R can be replaced by R1={photo,eye,nose,mouth} and R2={eye,nose,mouth,name,address}, on which mfd1: photo_g1(t1) -> {eye, nose, mouth}_g3(t3), and mfd2: {eye, nose, mouth}_g3(t3) -> {name, address}_g2(t2) hold, respectively.