Questions and answers for exam Preparation

MCQs

Total Questions : 10

Question 1. Which-one ofthe following statements about normal forms is FALSE?

BCNF is stricter than 3 NF
Lossless, dependency -preserving decomposition into 3 NF is always possible
Loss less, dependency "“ preserving decomposition into BCNF is always possible
Any relation with two attributes is BCNF View Answer

Discuss Question

Answer: Option A. -> BCNF is stricter than 3 NF

Loss less, dependency “ preserving decomposition into BCNF is always possibleWe say that the decomposition is a lossless decomposition if there is no loss of information by replacing r (R) with two relation schemas r1(R1) andr2(R2).

Question 2. In the __________ normal form, a composite attribute is converted to individual attributes.

First
Second
Third
Fourth

Discuss Question

Answer: Option A. -> First

FirstThe first normal form is used to eliminate the duplicate information.

Question 3. A table on the many side of a one to many or many to many relationship must:

Be in Second Normal Form (2NF)
Be in Third Normal Form (3NF)
Have a single attribute key
Have a composite key

Discuss Question

Answer: Option D. -> Have a composite key

Have a composite keyThe relation in second normal form is also in first normal form and no partial dependencies on any column in primary key.

Question 4. Tables in second normal form (2NF):

Eliminate all hidden dependencies
Eliminate the possibility of a insertion anomalies
Have a composite key
Have all non key fields depend on the whole primary key

Discuss Question

Answer: Option A. -> Eliminate all hidden dependencies

Eliminate all hidden dependenciesThe relation in second normal form is also in first normal form and no partial dependencies on any column in primary key.

Question 5. Functional Dependencies are the types of constraints that are based on______

Key
Key revisited
Superset key
None of these

Discuss Question

Answer: Option A. -> Key

KeyKey is the basic element needed for the constraints.

Question 6. Which is a bottom-up approach to database design that design by examining the relationship between attributes:

Functional dependency
Database modeling
Normalization
Decomposition

Discuss Question

Answer: Option C. -> Normalization

NormalizationNormalisation is the process of removing redundancy and unwanted data.

Question 7. 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

1 NF only
2 NF and hence also in 1 NF
3NF and hence also in 2NF and 1NF
BCNF and hence also in 3NF, 2NF and 1NF View Answer

Discuss Question

Answer: Option B. -> 2 NF and hence also in 1 NF

2 NF and hence also in 1 NFThe relation in second normal form is also in first normal form and no partial dependencies on any column in primary key.

Question 8. Which forms simplifies and ensures that there is minimal data aggregates and repetitive groups:

1NF
2NF
3NF
All of the mentioned

Discuss Question

Answer: Option C. -> 3NF

3NFThe first normal form is used to eliminate the duplicate information.

Question 9. Which forms has a relation that possesses data about an individual entity:

Discuss Question

Answer: Option C. -> 4NF

4NFA Table is in 4NF if and only if, for every one of its non-trivial multivalued dependencies X \twoheadrightarrow Y, X is a superkey”that is, X is either a candidate key or a superset thereof.

Question 10. Which forms are based on the concept of functional dependency:

Discuss Question

Answer: Option C. -> 3NF

3NFThe table is in 3NF if every non-prime attribute of R is non-transitively dependent (i.e. directly dependent) on every superkey of R.