What is Normalization? Normalization is a method used in organizing data inside a database. It breaks down big tables into smaller, simpler tables and links them. This method helps avoid duplicate data and ensures that all data is stored clearly and logically. By doing this, databases can work better because they don't have unnecessary or repeated information.

Benefits of Normalization:

Clearer Data: Data is organized more clearly, which helps in managing and using the data effectively.
Avoids Problems: Reduces problems like data being wrong or missing when you add, delete, or change data.
Saves Space: It uses the storage space more efficiently.

What is Denormalization? Denormalization is a technique used to speed up how fast you can get data from a database. It does this by allowing some duplicate data. By combining tables and adding duplicate data, databases can find information faster, which is useful when you need to get a lot of data quickly.

Benefits of Denormalization:

Faster Data Access: This helps you get data faster, which is useful for reports or analysis that need quick access to large amounts of information.
Simpler Queries: This makes writing database queries simpler because data that needs to be accessed together is kept together.

When to Use Each:

Normalization is usually better when you need to make sure your data is very accurate and stored efficiently, like in systems where data is constantly being added or changed.
Denormalization might be better in situations where you need to read data a lot and fast, like in systems that generate reports or handle lots of searches.

Example

Denormalized "Students" Table Structure

StudentID	Name	Email	Password	Section	Subjects	Professors	GWA	IsActive	LsEnrolled	IsSuspended	Address	Phone	BirthDate	EmergencyContact	RegistrationDate	AdvisorName
1	John Doe	johndoe@example.com	pass1234	A1	Math, Science	Dr. Smith, Prof. Lee	3.5	true	2023-08	false	123 Elm St	123-456-7890	2000-01-01	123-456-7891	2020-08-01	Dr. Allen
2	Jane Smith	janes@example.com	pass5678	A2	English, History	Prof. Kent, Dr. Jones	3.7	true	2023-08	false	456 Maple Ave	234-567-8901	1999-02-15	234-567-8902	2019-09-01	Prof. Carter
3	Alice Johnson	alicej@example.com	pass91011	A1	Science, PE	Dr. Smith, Coach Ray	3.8	false	2023-08	true	789 Oak Blvd	345-678-9012	2001-03-30	345-678-9013	2021-01-15	Dr. Harris
4	Bob Brown	bobb@example.com	pass1213	A2	Math, English	Dr. Lee, Prof. Kent	3.2	true	2023-08	false	321 Pine Rd	456-789-0123	2000-05-25	456-789-0124	2022-07-10	Prof. Sanders
5	Carol White	carolw@example.com	pass1415	A1	History, Science	Dr. Jones, Dr. Smith	3.9	true	2023-08	false	654 Spruce Ln	567-890-1234	1998-07-09	567-890-1235	2018-08-20	Dr. Murphy
6	Dave Green	daveg@example.com	pass1617	A2	PE, Math	Coach Ray, Dr. Lee	2.9	false	2023-08	true	987 Cedar St	678-901-2345	2002-09-17	678-901-2346	2023-01-05	Prof. Thompson
7	Eva Black	evab@example.com	pass1819	A1	English, PE	Prof. Kent, Coach Ray	3.6	true	2023-08	false	321 Birch St	789-012-3456	2001-11-23	789-012-3457	2022-06-15	Dr. Allen
8	Frank Gray	frankg@example.com	pass2021	A2	History, Math	Dr. Jones, Dr. Lee	3.1	true	2023-08	false	213 Willow Rd	890-123-4567	1997-12-31	890-123-4568	2017-09-25	Prof. Carter
9	Grace Hill	graceh@example.com	pass2223	A1	Science, History	Dr. Smith, Dr. Jones	4.0	false	2023-08	true	132 Elm St	901-234-5678	2002-02-20	901-234-5679	2021-10-30	Dr. Harris
10	Henry Lake	henryl@example.com	pass2425	A2	English, PE	Prof. Kent, Coach Ray	2.8	true	2023-08	false	312 Maple Ave	012-345-6789	1999-04-05	012-345-6790	2019-12-05	Prof. Sanders

Normalization Table Structure

`1. Students Table`

StudentID	Name	Email	Password	BirthDate	IsActive	LsEnrolled	IsSuspended
1	John Doe	johndoe@example.com	pass1234	2000-01-01	true	2023-08	false
2	Jane Smith	janes@example.com	pass5678	1999-02-15	true	2023-08	false
...	...	...	...	...	...	...	...

2. Address Table

AddressID	StudentID	Address	Phone	EmergencyContact
1	1	123 Elm St	123-456-7890	123-456-7891
2	2	456 Maple Ave	234-567-8901	234-567-8902
...	...	...	...	...

3. Subjects Table

SubjectID	Name
1	Math
2	Science
...	...

Enrollments Table

5. Professors Table

ProfessorID	Name
1	Dr. Smith
2	Prof. Lee
...	...

6. Advisors Table

Stores advisor information and links them to students.

AdvisorID	ProfessorID
1	1
2	2
...	...

7. Registrations Table

RegistrationID	StudentID	RegistrationDate	AdvisorID
1	1	2020-08-01	1
2	2	2019-09-01	2
...	...	...	...

Normalization Benefits:

Reduces Redundancy: Each piece of information exists only once in the database.
Improves Data Integrity: Updates have to be made in only one place, reducing the risk of inconsistent data.
Enhances Security: Can apply security measures to individual tables. For example, limiting access to the password table.

This normalized model minimizes redundancy by ensuring that each data element is stored only once. Relationships among the data are maintained through foreign keys

References:

GeeksforGeeks.

Difference between Normalization and Denormalization (tutorialspoint.com)

Normalization in SQL (1NF - 5NF): A Beginner’s Guide | DataCamp

Normalization and Denormalization in Databases