In relational database design, the different classes of relations created by the normalization technique for preventing update and modification anomalies are collectively called what?

Introduction / Context:
This question examines your knowledge of terminology related to normalization in relational database design. Normalization is a systematic process of organizing data to reduce redundancy and prevent update, insertion, and deletion anomalies. The stages or classes that a relation can achieve through normalization have a specific name that appears frequently in design theory and exams.

Given Data / Assumptions:

- The question mentions a technique for preventing modification anomalies.- It refers to different classes of relations produced by this technique.- We must identify the proper name for these classes.

Concept / Approach:
Normalization uses functional dependencies to analyze how attributes relate to keys and to each other. By decomposing relations according to rules, designers obtain relations that satisfy specific conditions. These stages are called normal forms and include first normal form, second normal form, third normal form, Boyce Codd normal form, and higher levels. The correct answer must therefore directly reference normal forms rather than underlying constraints such as functional dependencies or referential integrity.

Step-by-Step Solution:
Step 1: Recognize that the technique for preventing anomalies is called normalization.Step 2: Recall that normalization produces relations in stages called first normal form, second normal form, third normal form, and so on.Step 3: Understand that these stages are collectively known as normal forms.Step 4: Functional dependencies are used as a tool in the analysis but are not the classes themselves.Step 5: Referential integrity constraints govern relationships between tables but are separate from the classification into normal forms.Step 6: Therefore, the correct term for the classes of relations is normal forms.

Verification / Alternative check:
Database textbooks define first normal form, second normal form, third normal form, and higher forms as progressively stricter classes of relations. They repeatedly emphasize that the objective of normalization is to achieve suitable normal forms. Functional dependencies and referential integrity are defined separately as constraints and rules that support normalization and relational consistency, confirming the choice of normal forms as the answer.

Why Other Options Are Wrong:
Functional dependencies describe how attributes depend on each other, but they are not themselves classes of relations. Referential integrity constraints ensure that foreign keys correctly reference primary keys, which is important but different from normal form classification. Candidate keys identify minimal unique identifiers for tuples, and transaction logs record changes to the database. None of these represent the stages produced by the normalization process.

Common Pitfalls:
Students sometimes confuse the tools used in normalization with the results of the process. It is easy to mix up functional dependency analysis with the name of the resulting normal form. Keeping terminology clear helps when reading formal definitions and solving design problems. Always remember that normal forms are the labeled outcomes of the normalization process, such as 1NF, 2NF, and 3NF.

Final Answer:
The different classes of relations created by normalization are called normal forms.