Assignment 1: Task 3

Original Conceptual Design

The logical design is performed as a sequence of the following steps:

(1) The multivalued attributes are replaced with the classes of objects and, depending on the semantics of multivalued attributes, either with one-to-many or many-to-many associations

(2) The association classes and link attributes are replaced with the triples (one-to-many association:class-of-objects:many-to-one-association)

(3) Many-to-many associations are replaced with triples (one-to-many association:class-of-objects:many-to-one association)

(4) The qualifications are replaced with one-to-many associations and composite identifiers in object classes on the "many" side of one-to-many associations

(5) The selected identifiers are copied from the classes of objects on "one" side of the association to the classes of objects on "many" sides of the association and such identifiers are tagged with an FKn tag (an index "n" is used to distinguish between different foreign keys)

(6) The triples (class-of-objects: one-to-one association: class of objects) are merged into one class of objects, and one-to-one associations are removed

(7) The superset, subset and association methods are used to transform the generalizations

(8) The primary and candidate keys are created

(9) The associations are removed

(10) The relational schemas with the referential integrity constraints are created