Question 1

Normalization works through a series of stages called normal forms.

Accepted Answer

Normalization is a process that involves dividing a database into smaller and more manageable tables and removing redundant data. This process involves a series of normal forms that each have specific rules and guidelines for ensuring data integrity and reducing data redundancy. The most commonly used normal forms are first normal form (1NF), second normal form (2NF), and third normal form (3NF).

Question 2

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

Accepted Answer

Converting from 1NF to 2NF involves ensuring that all non-key attributes are fully functionally dependent on the primary key, which is a straightforward process if the database is already in 1NF.

Question 3

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

Accepted Answer

Normalization is actually a process used for organizing data in a database by eliminating redundant data and ensuring data dependencies make sense. It doesn't involve changing attributes to entities.

Question 4

Data redundancy produces data anomalies.

Accepted Answer

Data redundancy refers to the repetition of data in a database. It can result in data anomalies such as inconsistencies and errors, making it difficult to maintain data integrity and accuracy.

Question 5

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 6

In the context of partial dependencies, data redundancies occur because every row entry requires duplication of data.

Accepted Answer

Partial dependencies result in duplicated data in every row entry, leading to data redundancies.

Question 7

In order to meet performance requirements, portions of the database design may need to be occasionally denormalized.

Accepted Answer

Denormalization can sometimes be necessary to improve performance, especially in situations where a lot of complex queries are being run on the database. However, denormalizing should always be done with caution and a thorough understanding of the potential trade-offs.

Question 8

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

Accepted Answer

The statement is true. Fourth normal form builds on third normal form and adds the constraint that there should not be any independent multivalued dependencies in the table.

Question 9

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

Accepted Answer

Repeating groups violate the first normal form of database design, which requires that each row in a table contains a single value for each column. To eliminate repeating groups, the table must be restructured so that each row defines a single entity.

Question 10

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

Accepted Answer

This statement is true according to the definition of BCNF, which requires all determinants (attributes that determine other attributes) in a relation to be candidate keys.

Question 11

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 illustrate the relationships between attributes in a table, making them helpful for understanding the structure of a database.

Question 12

The objective of normalization is to ensure that each table conforms to the concept of well-formed relations.

Accepted Answer

The objective of normalization is to ensure that each table conforms to the concept of well-formed relations, which includes meeting certain rules such as having a primary key, avoiding redundant data, and ensuring data dependencies are properly represented.

Question 13

Denormalization produces a lower normal form.

Accepted Answer

Denormalization involves intentionally introducing redundancy into the database design to improve query performance. This results in a lowered normal form as some data is duplicated across multiple tables.

Question 14

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

Accepted Answer

A table is in BCNF if and only if for every one of its non-trivial functional dependencies X -> Y, X is a superkey. This condition does not require every determinant to be a foreign key.

Question 15

A dependency based on only a part of a composite primary key is known as a partial dependency.

Accepted Answer

A partial dependency occurs when a non-key attribute is functionally dependent on only a portion of the primary key, rather than the entire key.

Question 16

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 17

Reporting anomalies in a table can cause a multitude of problems for managers and can be fixed through application programming.

Accepted Answer

The answer of Reporting anomalies in a table can cause...

Question 18

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

Accepted Answer

Relational models view data as a set of tables with each row representing a record and each column representing a field or attribute. In a relational model, all entities are represented as tables and relationships among entities are established by storing common data in related tables. All key values must be identified in the tables, including primary keys and foreign keys to maintain data integrity.

Question 19

Normalization produces a lower normal form.

Accepted Answer

The answer of Normalization produces a lower normal form....

Question 20

All relational tables satisfy the 1NF requirements.

Accepted Answer

All relational tables must satisfy the first normal form (1NF) requirements, which includes having atomic values and no repeating groups or arrays. Therefore, all relational tables do indeed satisfy 1NF.

Quiz 6: Normalization of Database Tables