Question 1

Because a partial dependency can exist only if a table's primary key is composed of several attributes,if a table in 1NF has a single-attribute primary key,then the table is automatically in 2NF.

Accepted Answer

This is because in 2NF, a table is required to not have any partial dependencies on any part of the candidate key. If the primary key is a single attribute, then there can be no partial dependencies on any other attribute and thus the table is automatically in 2NF.

Question 2

Denormalization produces a lower normal form.

Accepted Answer

Denormalization involves introducing redundant data into a database, which can lead to a lower normal form, such as moving from third normal form (3NF) to second normal form (2NF) or even first normal form (1NF). However, denormalization is often used to improve performance and efficiency in certain scenarios.

Question 3

A table is in BCNF if every determinant in the table is a candidate key.

Accepted Answer

This is the definition of Boyce-Codd Normal Form.

Question 4

Converting a database format from 1NF to 2NF is a complex process.

Accepted Answer

Converting a database format from 1NF to 2NF involves identifying partial dependencies and removing them by creating separate tables for related data. While it can be a time-consuming process, it is not necessarily complex.

Question 5

In order to meet performance requirements,you may have to denormalize portions of the database design.

Accepted Answer

Denormalization is a technique used to improve performance in database systems where portions of the database schema are deliberately duplicated or reorganized to improve data retrieval speeds. Denormalization is often used to meet performance requirements in large databases.

Question 6

Normalization works through a series of stages called normal forms.

Accepted Answer

Normalization does work through a series of stages called normal forms, with each higher normal form providing additional rules and guidelines for reducing redundancy and improving data integrity in a database. The most commonly used normal forms are first normal form (1NF), second normal form (2NF), third normal form (3NF), and so on.

Question 7

Repeating groups must be eliminated by making sure that each row defines a single entity.

Accepted Answer

Repeating groups violate the first normal form of database design and must be eliminated to ensure that each row in a table defines a single entity. This is accomplished by creating a new table to represent the repeating group and establishing a foreign key relationship between the two tables.

Question 8

A table is in 2NF if it is in 1NF and it includes no partial dependencies.

Accepted Answer

In 2NF, all non-key attributes must depend on the entire primary key, not just part of it. This means there are no partial dependencies in the table. Therefore, the statement is true.

Question 9

All relational tables satisfy the 1NF requirements.

Accepted Answer

This is true because in order to be considered a relational table, the first normal form (1NF) requirement must be met, which includes having atomic values in each cell of the table.

Question 10

Normalization is a very important database design ingredient and the highest level is always the most desirable.

Accepted Answer

The answer of Normalization is a very important database design...

Question 11

Relational models view the data as part of a table or collection of tables in which all key values must be identified.

Accepted Answer

Relational models are based on tables, where each row represents a unique record and each column represents a specific attribute or characteristic of that record. Keys are used to identify and link information between tables. Therefore, all key values must be identified in order for the relational model to function properly.

Question 12

With parrtial dependencies,data redundancies occur because every row entry requires duplication of data.

Accepted Answer

When partial dependencies exist in a database, some attributes depend on only a part of the primary key, which leads to duplicate entries and data redundancies.

Question 13

A table is in BCNF if every determinant in the table is a foreign key.

Accepted Answer

A table is in BCNF if every non-trivial determinant in the table is a candidate key, not just any foreign key.

Question 14

Dependencies that are based on only a part of a composite primary key are called transitive dependencies.

Accepted Answer

Dependencies based on only a part of a composite primary key are called partial dependencies, not transitive dependencies. Transitive dependencies occur when a non-prime attribute is dependent on another non-prime attribute.

Question 15

Dependency diagrams are very helpful in getting a bird's-eye view of all the relationships among a table's attributes.

Accepted Answer

Dependency diagrams are graphical tools that show the relationships among the attributes of a table, making it easier to understand the dependencies between them. They are useful in identifying functional dependencies, determining normal forms, and designing efficient database schemas.

Question 16

Normalization produces a lower normal form.

Accepted Answer

Normalization produces a higher normal form by reducing or eliminating data redundancy and improving data integrity.

Question 17

It is possible for a table in 2NF to exhibit transitive dependency,where one or more nonprime attributes functionally determine other nonprime attributes.

Accepted Answer

The answer of It is possible for a table in...

Question 18

A table is in fourth normal form if it is in third normal form and has no independent multivalued dependencies.

Accepted Answer

This is the definition of fourth normal form.

Question 19

Repeating groups must be eliminated by making sure that each column defines a single entity.

Accepted Answer

The answer of Repeating groups must be eliminated by making...

Question 20

Normalization is a process that is used for changing attributes to entities.

Accepted Answer

Normalization is a process that is used for organizing data in a database by creating tables and establishing relationships between them to optimize efficiency and reduce data redundancy. It is not used for changing attributes to entities.

Quiz 6: Normalization of Database Tables