Normalization in DBMS

A functional dependency is a relationship between or among

• A. Entities

• B. Rows

• C. Attributes

• D. Tables

Which functional dependency types is/are not present in the following dependencies?

Empno -> EName, Salary, Deptno, DName

DeptNo -> DName

EmpNo -> DName

• A. Full functional dependency

• B. Partial functional dependency

• C. Transitive functional dependency

• D. Both B and C

If one attribute is determinant of second, which in turn is determinant of third, then the relation cannot be:

• A. Well-structured

• B. 1NF

• C. 2NF

• D. 3NF

Consider the schema R(S,T,U,V) and the dependencies S→T, T→U, U→V, V→S. Let R= {R1,R2} such that R1∩R2=Φ. Then the decomposition is :

• A. not in 2NF

• B. in 2NF but not in 3NF

• C. in 3NF but not in 2NF

• D. in both 2NF and 3NF

In the __________ normal form, a composite attribute is converted to individual attributes.

• a) First

• b) Second

• c) Third

• d) Fourth

Functional Dependencies are the types of constraints that are based on______

• a) Key

• b) Key revisited

• c) Superset key

• d) None of the mentioned

Empdt1(empcode, name, street, city, state, pincode).

For any pincode, there is only one city and state. Also, for given street, city and state, there is just one pincode. In normalization terms, empdt1 is a relation in

• a) 1 NF only

• b) 2 NF and hence also in 1 NF

• c) 3NF and hence also in 2NF and 1NF

• d) BCNF and hence also in 3NF, 2NF and 1NF

There are two functional dependencies with the same set of attributes on the left side of the arrow:

A->BC

A->B

This can be combined as

• a) A->BC

• b) A->B

• c) B->C

• d) None of the mentioned

Consider a relation R(A,B,C,D,E) with the following functional dependencies:

ABC -> DE and

D -> AB

The number of superkeys of R is:

• 2

• 7

• 10

• 12

Suppose relation R(A,B,C,D,E) has the following functional dependencies:

A -> B

B -> C

BC -> A

A -> D

E -> A

D -> E

Which of the following is not a key?

• a) A

• b) E

• c) B, C

• d) D