Q.1 What is the main purpose of database normalization?
To reduce data redundancy and improve data integrity
To increase the size of the database
To make queries slower
To duplicate data across tables
Explanation - Normalization organizes data to minimize redundancy and ensures data consistency by splitting tables based on functional dependencies.
Correct answer is: To reduce data redundancy and improve data integrity
Q.2 Which normal form eliminates repeating groups from a table?
1NF
2NF
3NF
BCNF
Explanation - First Normal Form (1NF) requires that the table have no repeating groups or arrays, and that each field contains only atomic values.
Correct answer is: 1NF
Q.3 A table is in 2NF if it is in 1NF and...
Has no partial dependency
Has no transitive dependency
Has no candidate keys
Has no foreign keys
Explanation - Second Normal Form (2NF) requires that every non-prime attribute be fully functionally dependent on the primary key, eliminating partial dependencies.
Correct answer is: Has no partial dependency
Q.4 Which normal form removes transitive dependency?
1NF
2NF
3NF
BCNF
Explanation - Third Normal Form (3NF) requires that non-key attributes be dependent only on the primary key and not on other non-key attributes, removing transitive dependencies.
Correct answer is: 3NF
Q.5 Boyce-Codd Normal Form (BCNF) is stricter than which normal form?
1NF
2NF
3NF
4NF
Explanation - BCNF resolves anomalies that 3NF may not handle, specifically when a non-trivial functional dependency exists with a determinant that is not a super key.
Correct answer is: 3NF
Q.6 What is a partial dependency?
When a non-prime attribute depends on part of a composite primary key
When a primary key depends on a non-prime attribute
When an attribute depends on a foreign key
When all attributes are fully dependent on the primary key
Explanation - Partial dependency occurs when a non-key attribute is dependent on only a portion of a composite primary key.
Correct answer is: When a non-prime attribute depends on part of a composite primary key
Q.7 Which of the following is a violation of 1NF?
Having a table column that contains multiple phone numbers in a single field
Having multiple tables linked by foreign keys
Having a primary key
Having unique constraints
Explanation - 1NF requires that each column holds atomic (indivisible) values, so storing multiple values in one column violates 1NF.
Correct answer is: Having a table column that contains multiple phone numbers in a single field
Q.8 Transitive dependency occurs when...
A non-prime attribute depends on another non-prime attribute
A primary key depends on a foreign key
All attributes depend on the primary key
There are repeating groups
Explanation - Transitive dependency exists when a non-key attribute depends on another non-key attribute rather than depending directly on the primary key.
Correct answer is: A non-prime attribute depends on another non-prime attribute
Q.9 Which normal form deals with multi-valued dependencies?
3NF
BCNF
4NF
5NF
Explanation - Fourth Normal Form (4NF) removes multi-valued dependencies to prevent redundancy caused by independent multi-valued facts.
Correct answer is: 4NF
Q.10 A table in which all determinants are candidate keys is in...
2NF
3NF
BCNF
4NF
Explanation - BCNF requires that every determinant in the table is a candidate key, which eliminates certain anomalies not addressed by 3NF.
Correct answer is: BCNF
Q.11 Which of the following is true for 1NF?
All values must be atomic
No transitive dependency
No partial dependency
All non-key attributes depend on candidate keys
Explanation - 1NF requires that table fields contain atomic values with no repeating groups or arrays.
Correct answer is: All values must be atomic
Q.12 The process of decomposing a table into multiple tables to achieve normalization is called...
Indexing
Partitioning
Decomposition
Clustering
Explanation - Decomposition breaks down a table into smaller tables to eliminate redundancy and maintain data integrity according to normal forms.
Correct answer is: Decomposition
Q.13 Which normal form is primarily concerned with ensuring that every determinant is a candidate key?
1NF
2NF
3NF
BCNF
Explanation - BCNF strengthens 3NF by ensuring that all determinants are candidate keys, resolving certain anomalies 3NF cannot.
Correct answer is: BCNF
Q.14 A table is in 3NF if it is in 2NF and...
Has no partial dependencies
Has no transitive dependencies
Has no multi-valued dependencies
Has no foreign keys
Explanation - 3NF removes transitive dependencies to ensure non-key attributes depend only on the primary key.
Correct answer is: Has no transitive dependencies
Q.15 What is a multivalued dependency?
When one attribute in a table uniquely determines another attribute
When an attribute in a table determines multiple independent attributes
When a primary key depends on a foreign key
When all attributes are dependent on a single key
Explanation - A multivalued dependency exists when one attribute determines multiple independent attributes, which is addressed in 4NF.
Correct answer is: When an attribute in a table determines multiple independent attributes
Q.16 Which normal form is concerned with joining tables to recover original data without loss?
1NF
2NF
4NF
5NF
Explanation - Fifth Normal Form (5NF) ensures that tables can be decomposed and joined without losing information, dealing with join dependencies.
Correct answer is: 5NF
Q.17 Anomalies in insertion, deletion, and update are minimized by...
Denormalization
Normalization
Indexing
Replication
Explanation - Normalization organizes data to remove redundancies and dependencies, reducing anomalies during database operations.
Correct answer is: Normalization
Q.18 If a table has only a single candidate key with no dependencies, it is in which normal form?
1NF
2NF
3NF
BCNF
Explanation - If all determinants are candidate keys and there are no other anomalies, the table satisfies BCNF.
Correct answer is: BCNF
Q.19 Which normal form is stricter than 4NF?
1NF
2NF
5NF
BCNF
Explanation - Fifth Normal Form (5NF) addresses join dependencies and ensures lossless decomposition beyond 4NF.
Correct answer is: 5NF
Q.20 A table with no repeating groups but with partial dependency is in...
1NF
2NF
3NF
BCNF
Explanation - Such a table satisfies 1NF because it has atomic values but violates 2NF due to partial dependencies.
Correct answer is: 1NF
Q.21 Which of the following is a characteristic of 2NF?
Eliminates repeating groups
Eliminates partial dependencies
Eliminates transitive dependencies
Eliminates multivalued dependencies
Explanation - 2NF removes partial dependencies, ensuring that non-key attributes are fully dependent on the primary key.
Correct answer is: Eliminates partial dependencies
Q.22 Which normal form would be used to handle a table containing independent multi-valued facts?
3NF
BCNF
4NF
5NF
Explanation - 4NF deals with independent multivalued facts to prevent redundancy caused by multi-valued dependencies.
Correct answer is: 4NF
Q.23 If every non-prime attribute is fully functionally dependent on the primary key and there are no transitive dependencies, the table is in...
2NF
3NF
BCNF
4NF
Explanation - 3NF requires full functional dependency on the primary key and no transitive dependencies among non-key attributes.
Correct answer is: 3NF
Q.24 Which type of dependency violates 2NF but not necessarily 1NF?
Partial dependency
Transitive dependency
Multivalued dependency
Join dependency
Explanation - 2NF eliminates partial dependencies where non-key attributes depend only on part of a composite primary key, which 1NF does not address.
Correct answer is: Partial dependency