Chapter 2, Problem 2.40E

A)

Explanation of Solution

Table of example of students, one who has three siblings and other has two siblings:

StudentNumber	StudentName	SiblingName	Major
10	Nick Jones

B)

Explanation of Solution

Candidate keys in the student relational table:

(StudentNumber,SiblingName) acts as candidate key for the Student Relational as using StudentNumber an...

C)

Explanation of Solution

Functional dependencies in the relation:

• StudentNumber-> (StudentName, Major)
  • Here the composite attributes StudentName and Major are functionally dependent on the attribute StudentNumber.
  • The attribute StudentNumber determines the composite attribute StudentName and Major...

D)

Explanation of Solution

Well-formed relation:

The relations that do meet the relational design criteria are well-formed relations.

• The relational Student table contains the functional dependencies: StudentNumber-> (StudentName, Major) and (StudentNumber, SiblingName) -> (StudentName, Major)...

E)

Explanation of Solution

4NF:

If in a relation there is no non-trivial multivalued dependency, other than a candidate key, the level of database normalization is in fourth normal form or 4NF.

4NF and set of well-formed relations:

A relational table is not a well formed relation if in the relation some attributes of the tuple are functionally dependent on a part of the composite primary key...

F)

Explanation of Solution

Divide the relation to form a set of well-formed relations:

Step-1: Break the student tuple into two relations: Student and StudentSibling.

Show the relations in each table:

STUDENT (StudentNumber, StudentName, Major) and STUDENT-SIBLING (StudentNumber, SiblingName)

• For StudentSibling relation, show the functional dependencies among relations:
• (StudentNumber, SiblingName) -> (StudentNumber)

Here, the attribute StudentNumber is functionally dependent on the composite attribute (StudentNumber, SiblingName).

The composite attribute (StudentNumber, SiblingName) determines the attribute StudentNumber.

(StudentNumber, SiblingName)->(SiblingName)

Here, the attribute SiblingName is functionally dependent on the composite attribute (StudentNumber, SiblingName).

The composite attribute (StudentNumber, SiblingName) determines the attribute StudentNumber.

Check the candidate keys for StudentSibling relation:

(StudentNumber,SiblingName) acts as a candidate key for the StudentSibling relation...