Normalization Is An Important Step In Translating Models

Normalization Is An Important Step Towards Translating Models And Diag

Normalization is an important step towards translating models and diagrams into relational databases. In this exercise, you will need to normalize the Grade_Report table below and explain the steps needed to do so. For this assessment, consider the following entity and its attributes and normalize the entity Grade_Report to 3NF. Entity : Grade_Report (StudentID, StudentName, Phone, DOB, Address, Email_Address, CourseNumber, CourseName, Grade, DepartmentID, DepartmentName) Explain the steps needed to normalize this entity to 1NF, 2NF and 3NF. List the resultant Normalized entities in the same format as the original Grade_Report. Once the entity is normalized to 3NF, describe any issues this entity might have that can be solved by normalization. Explain the functional dependencies that exist between the attributes. Provide the steps required to break up the Grade_Report entity into multiple entities that each have a single theme.

Paper For Above instruction

Introduction

Normalization is a fundamental process in designing relational databases that ensures data is structured efficiently, reduces redundancy, and maintains data integrity. This process involves transforming a database table into progressively higher normal forms—First Normal Form (1NF), Second Normal Form (2NF), and Third Normal Form (3NF)—each adding stricter criteria to eliminate undesirable characteristics such as redundancy and update anomalies. In this paper, we analyze the normalization process of the Grade_Report table containing multiple attributes related to students, courses, and departments. We will systematically normalize the table from an unnormalized entity to 3NF, explore the potential issues that might still persist even after normalization, and discuss how to decompose it further into thematically cohesive entities.

Initial Structure and First Normal Form (1NF)

The original Grade_Report table comprises attributes including StudentID, StudentName, Phone, DOB, Address, Email_Address, CourseNumber, CourseName, Grade, DepartmentID, DepartmentName. The initial step in normalization involves ensuring that the table adheres to 1NF, which requires that all attribute values are atomic—indivisible and scalar—and that there are no repeating groups or arrays within the table.

In the initial table, each row contains a student's details alongside the course they're enrolled in and the department information. If a student enrolls in multiple courses, there could be multiple rows with repeating student information, indicating partial redundancy. To conform to 1NF, the data must be organized such that each cell contains only a single value, and multi-valued attributes, if any, are separated into distinct rows or tables. Given the table's structure, assuming each row represents a unique student-course pairing, the table is in 1NF, as all values are atomic.

Second Normal Form (2NF) and Functional Dependencies

Achieving 2NF involves eliminating partial dependencies—that is, attributes that depend on only part of a composite primary key. Considering that each record is uniquely identified by StudentID and CourseNumber, this composite key determines other attributes. However, certain attributes like StudentName, Phone, DOB, Address, and Email_Address depend solely on StudentID, and CourseName, DepartmentID, DepartmentName depend only on CourseNumber.

This indicates that the table contains partial dependencies. Specifically:

- Student-related attributes depend solely on StudentID.

- Course-related attributes depend solely on CourseNumber.

- DepartmentName depends on DepartmentID, which in turn depends on CourseNumber via the course's department.

Therefore, to normalize to 2NF, we need to decompose the table into smaller related entities such as Student, Course, Department, and Enrollment tables.

Third Normal Form (3NF) and Removing Transitive Dependencies

Normalization to 3NF requires removing transitive dependencies—dependencies where non-key attributes depend on other non-key attributes. For instance, DepartmentName depends on DepartmentID, which depends on CourseNumber, implying a transitive dependency chain.

To achieve 3NF:

- Separate the Department information into a distinct Department table with DepartmentID and DepartmentName.

- Create a Course table with CourseNumber, CourseName, and DepartmentID (foreign key).

- Maintain a Student table with StudentID, StudentName, Phone, DOB, Address, and Email_Address.

- Create an Enrollment table linking StudentID and CourseNumber, including the Grade.

The final normalized schema would likely include:

- Students(StudentID, StudentName, Phone, DOB, Address, Email_Address)

- Departments(DepartmentID, DepartmentName)

- Courses(CourseNumber, CourseName, DepartmentID)

- Enrollments(StudentID, CourseNumber, Grade)

These tables reduce redundancy, organize data thematically, and ensure dependencies are correctly managed.

Issues Remaining After 3NF and Further Decomposition

Despite normalization to 3NF, some issues may still persist, such as data anomalies or difficulty in querying related data efficiently. Further decomposition can improve clarity and maintainability by aligning modules with real-world entities and themes.

The remaining issues involve:

- Data inconsistency if DepartmentID and DepartmentName are stored separately but not synchronized.

- Complex joins needed to retrieve full reports, which could be optimized through denormalization depending on application needs.

To further refine the design, each entity can be broken into specialized modules:

- Student entity capturing student details.

- Course entity encapsulating course data and associated department.

- Department entity encapsulating department information.

- Enrollment linking students, courses, and grades.

Functional Dependencies and Decomposition Steps

The functional dependencies can be summarized as:

- StudentID → StudentName, Phone, DOB, Address, Email_Address

- CourseNumber → CourseName, DepartmentID

- DepartmentID → DepartmentName

- (StudentID, CourseNumber) → Grade

Decomposition steps involve:

1. Creating the Student table with attributes dependent solely on StudentID.

2. Creating the Department table with DepartmentID and DepartmentName.

3. Creating the Course table with CourseNumber, CourseName, and DepartmentID.

4. Creating the Enrollment table with StudentID, CourseNumber, and Grade to record each student's performance.

This approach ensures that each table captures a single theme, that is, students, courses, departments, and enrollments, aligning with principles of normalization.

Conclusion

Normalizing the Grade_Report table from its unnormalized state to 3NF significantly improves data integrity, reduces redundancy, and aligns database structure with real-world entities. While 3NF addresses many issues related to dependencies and anomalies, further thematic decomposition enhances modularity and clarity. Understanding and applying functional dependencies allows database designers to structure data efficiently and intuitively, supporting reliable and scalable database applications.

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