Functional Dependencies and Normalization MCQs Flashcards
(30 cards)
What is the purpose of normalization?
o A) To increase data redundancy
o B) To reduce data duplication and enhance data integrity
o C) To improve query performance
o D) To simplify database design
To reduce data duplication and enhance data integrity
What is a transitive dependency?
o A) A dependency of a non-key attribute on another non-key attribute
o B) A dependency of a key attribute on a non-key attribute
o C) A direct dependency between primary keys
o D) None of the above
A dependency of a non-key attribute on another non-key attribute
What is Boyce-Codd Normal Form (BCNF)?
o A) A stricter version of 3NF
o B) A form that allows transitive dependencies
o C) A form with no functional dependencies
o D) None of the above
A stricter version of 3NF
Which of the following is NOT a characteristic of functional dependencies?
o A) Reflexivity
o B) Transitivity
o C) Union
o D) Redundancy
Redundancy
What is the main goal of the third normal form (3NF)?
o A) To remove all redundancies
o B) To ensure all attributes are dependent on the primary key
o C) To prevent transitive dependencies
o D) To allow partial dependencies
To prevent transitive dependencies
Which of the following is a candidate key?
o A) A key that can uniquely identify a record
o B) A key that is a foreign key
o C) A key that has multiple values
o D) A key that is always null
A key that can uniquely identify a record
Which normal form requires that all functional dependencies be fully functional?
o A) 1NF
o B) 2NF
o C) 3NF
o D) BCNF
2NF
What is a primary key?
o A) A unique identifier for a table
o B) A foreign key that references another table
o C) An attribute that can have null values
o D) A composite key made of multiple attributes
A unique identifier for a table
Which of the following is a violation of 2NF?
o A) A composite primary key with non-key attributes
o B) A single attribute as the primary key
o C) All attributes dependent on the primary key
o D) No partial dependencies
A composite primary key with non-key attributes
What is the outcome of normalization?
o A) Increased redundancy
o B) Simplified queries
o C) Enhanced data integrity
o D) All of the above
Enhanced data integrity
Which of the following describes a surrogate key?
o A) A key derived from business data
o B) A system-generated unique identifier
o C) A composite key
o D) A foreign key
A system-generated unique identifier
What is denormalization?
o A) The process of organizing data to reduce redundancy
o B) The introduction of redundancy for performance purposes
o C) The removal of all keys
o D) The creation of new tables
The introduction of redundancy for performance purposes
Which of the following statements is true about functional dependencies?
o A) They can exist without primary keys.
o B) They are always transitive.
o C) They are only relevant in 1NF.
o D) They can be violated in BCNF.
They can exist without primary keys.
Which normal form eliminates transitive dependencies?
o A) 1NF
o B) 2NF
o C) 3NF
o D) 4NF
3NF
What is the main purpose of using composite keys?
o A) To simplify database design
o B) To uniquely identify records when a single attribute is insufficient
o C) To reduce the number of tables
o D) To enforce data integrity
To uniquely identify records when a single attribute is insufficient
What is a functional dependency closure?
o A) The set of all attributes that can be functionally determined by a set of
o B) The elimination of all functional dependencies
o C) The process of creating new functional dependencies
o D) None of the above
The set of all attributes that can be functionally determined by a set of
Which normalization form does not allow any multi-valued dependencies?
o A) 1NF
o B) 2NF
o C) 3NF
o D) 4NF
4NF
What signifies a relation being in 1NF?
o A) All attributes are unique
o B) All attributes are atomic
o C) No transitive dependencies
o D) All functional dependencies are preserved
All attributes are atomic
What is a foreign key?
o A) A key that uniquely identifies a record within its own table
o B) A key that links two tables together
o C) A key that can accept null values
o D) A primary key from another table
A key that links two tables together
Which of the following is an advantage of normalization?
o A) Increased complexity
o B) Reduced redundancy
o C) Slower queries
o D) All of the above
Reduced redundancy
What is the main goal of functional dependency analysis?
o A) To create new tables
o B) To identify relationships among attributes
o C) To optimize query performance
o D) To enforce data integrity
To identify relationships among attributes
In which normal form can a relation have no non-prime attributes?
o A) 1NF
o B) 2NF
o C) 3NF
o D) BCNF
BCNF
In relation to database design, what does “lossless decomposition” refer to?
o A) Breaking down a table without losing data
o B) Combining tables to reduce redundancy
o C) Creating a single table from multiple tables
o D) None of the above
Breaking down a table without losing data
Which normal form is achieved by eliminating multi-valued dependencies?
o A) 1NF
o B) 2NF
o C) 3NF
o D) 4NF
4NF
