Normalization
Transitive dependencies make which of the following invalid?
3NF and BCNF
Which of the following normal forms provides the most stringent rules against which a relation is tested?
4NF
Which of the following is required before the normalization process can be applied to a relational database?
Each instance of an entity must have a primary key that uniquely identifies that entity.
What is an atomic value?
An attribute's value that cannot be divided into multiple pieces of information
How is the normalization process usually performed?
As a sequence of tests on a relation to determine whether it meets the criteria of a particular normal form
What is the term for an attribute's value that cannot be divided into multiple pieces of information?
Atomic value
In a functional dependency, which of the following describes the situation in which B is functionally dependent on A, and the dependency still exists when an attribute is removed from A?
B is partially functionally dependent on A.
The student_id attribute is the primary key of the following table. What is the highest normal form of this relation?
BCNF
Which of following is designed to address the situation in which a functional dependency remains on candidate keys within a relation?
BCNF
What is the term for the process of creating new relations from existing relations based on functional dependencies within the original relation?
Decomposition
What is the term for the process of rejoining relations that were decomposed during normalization?
Denormalization
For which of the following would the only requirement be that the data in a two-dimensional table contain attributes represented by atomic values?
First normal form
What is the term for a relationship between two attributes in which there is only one value of attribute B for each unique attribute A?
Functional dependency
What is the term for a number of special properties or constraints that a relation must possess to achieve certain desired goals, such as minimizing unwanted data redundancy?
Normal form
Which of the following provides a mechanism by which the database design can accurately represent the data, relationships and constraints of an enterprise?
Normalization
The student_id attribute is the primary key of the following table. Which of the following statements about the remaining attributes in the student relation are true?
The remaining attributes are fully functionally dependent on the primary key.
Your database environment consists of large databases and complex queries. Why might you consider denormalizing your database relations?
To improve database performance, especially during query operations
Which of the following problems is the normalization process designed to address?
Unwanted data redundancy in a relational database
In a functional dependency, what does it mean when B is partially dependent on A?
When an attribute is removed from A, the dependency still exists.
A relation is said to be in second normal form when the relation is in 1NF and:
all attributes that are not part of the primary key are completely functionally dependent on the primary key.
A relation is in BCNF if and only if:
all determinants are candidate keys.
A relation is said to be in first normal form when:
an attribute's value is indivisible.
A relation is said to be in 3NF if it is in 2NF and:
no transitive dependencies exist in the relations.
Normalization usually has the effect of:
reducing the duplication of data items within the database.
A relation that is in 1NF is automatically in 2NF when:
the relation has a single attribute as its primary key.
At which stage of the normalization process would you use decomposition to remove undesirable functional dependencies by creating additional relations?
2NF
Any relation in which every attribute is part of the primary key is automatically in:
2NF.
Most database designers attempt to normalize the database to conform to which normal form?
3NF
What is a determinant attribute?
An attribute on which another attribute is functionally dependent
For which of the following are relations still subject to insertion, deletion and update anomalies?
First normal form
Which of the following statements about normal forms is true?
In theory, the higher the normal form, the stronger the design of the database.
Relations that are in 1NF are often subject to insertion, deletion and update anomalies. What can you do to solve this problem?
Place the relation in 2NF.
What should you do if the normalization process decomposes relations to the point where a determinant is separated from its dependent attributes resulting in a loss of functional dependencies?
Stop the normalization process at 3NF.
Which of the following is a common occurrence when you normalize a relational database?
The amount of storage space needed for the base tables of the database will decrease.
Normalization is a process that occurs during which phase of the database design process?
The logical design phase
In a functional dependency, which of the following describes the situation in which B is functionally dependent on A, and C is functionally dependent on B?
C is transitively dependent on A.
