Normalization
Below is an example of a denormalized table representing all information in one large relation. Notice that several columns contain multiple values (images, colors, addresses, products, etc.), which violates First Normal Form.
| order_num | client_name | client_email | delivery_address | product_code(s) | product(s) | product_images | product_colors | product_price | order_quantity | store_ID | store_name | store_rating | employee | store_owner | order_status | payment | discount | review-comment | order_rating | request | request_problem | report_profit | monthly_profit | order_total | sales_trend
|
|---|
| 0012025000001 | Marija Kostova | marija@… | st.Turisticka 5, Bitola | 00100001 | Handmade Wooden Chair | chair.jpg | Brown | 700 | 1 | 001 | WoodCraft Skopje | 4.6 | Antonio Trajkovski | Marko Petrovski | Delivered | Cash | 0.04 | Great quality, slightly late delivery | 4.5 | 001112025001 | Late delivery | 125000 | 12500 | 700 | Increasing
|
| 0022025000001 | Ivan Stojanov | ivan@… | st.Partizanska 10, Skopje | 00200002 | Decorative Wall Hanging | wall_hanging.jpg | White & Pink, Black & Gold, Orange-Green-Purple | 199 | 2 | 002 | Fox Crochets | 4.8 | Sara Vaneva | Sara Vaneva | Placed Order | Credit Card | 0.0 | Excellent craftsmanship | 5.0 | 002122025001 | Military Discount | 98000 | 8000 | 350 | Stable
|
| 0022025000002 | Ivan Stojanov | ivan@… | st.Partizanska 10, Skopje | 00200001 | Heart Crochet | crochet-heart-red.jpg, crochet-heart-blue.jpg | Blue, Red, Yellow, Green | 150 | 3 | 002 | Fox Crochets | 4.8 | Sara Vaneva | Sara Vaneva | Packaging | PayPal | 0.0 | Beautiful handmade product | 5.0 | — | — | 98000 | 8000 | 50 | Stable
|
| 0012025000002 | Antoneta Mariovska | mariovskaantoneta@… | st.32 4, s.Cucer-Sandevo | 00100001,00200001 | Wooden Chair, Heart Crochet | chair.jpg, crochet-heart-red.jpg | Brown, Blue, Red | 850 | 2 | 001,002 | WoodCraft Skopje & Fox Crochets | 4.0 | Antonio Trajkovski | Marko Petrovski | Packaging | Credit Card | 0.05 | Very satisfied | 5.0 | 003122025001 | Packaging question | 223000 | 20500 | 750 | Increasing
|
| 0022025000003 | Ivan Stojanov | ivan@… | st.Partizanska 10, Skopje | 00200002 | Decorative Wall Hanging | wall_hanging.jpg | Black & Gold | 199 | 1 | 002 | Fox Crochets | 4.8 | Sara Vaneva | Sara Vaneva | Placed Order | Credit Card | 0.02 | Wonderful decoration | 5.0 | 004122025001 | Shipping question | 98000 | 8000 | 350 | Stable
|
Problems with the Denormalized Table
This table contains several issues:
- Multiple products may appear in one order.
- A product may have multiple colors.
- A product may have multiple images.
- Client information repeats for every order.
- Store information repeats for every product sold.
- Employee and boss information repeats.
- Reports and profits repeat for every order.
- There are repeating groups, making updates difficult.
- Insertion, deletion, and update anomalies may occur.
Because of these problems, the table is not in First Normal Form.
To achieve 1NF:
- Every column must contain atomic values.
- No repeating groups.
- No lists inside cells.
- Every row represents exactly one occurrence.
Instead of storing several colors or images in one field, each value gets its own row.
CLIENT
| client_id | first_name | last_name | email
|
|---|
| 1 | Ivan | Stojanov | ivan@…
|
| 2 | Marija | Kostova | marija@…
|
| 3 | Antoneta | Mariovska | mariovskaantoneta@…
|
DELIVERY ADDRESS
| client_id | address
|
|---|
| 1 | st.Partizanska 10, 1000 Skopje
|
| 2 | st.Turisticka 5,7000 Bitola
|
| 3 | st.Ilindenska 20, 1000 Skopje
|
STORE
| store_ID | store_name | store_rating
|
|---|
| 001 | WoodCraft Skopje | 4.6
|
| 002 | Fox Crochets | 4.8
|
PRODUCT
| product_code | description | price | weight | delivery_cost
|
|---|
| 00100001 | Handmade wooden chair with oak wood | 700 | 2.5 | 50
|
| 00200001 | Heart crochet | 50 | 0.2 | 0
|
| 00200002 | Decorative wall hanging made with beads | 350 | 0.75 | 0
|
PRODUCT COLORS
| product_code | description | price | weight | delivery_cost
|
|---|
| 00100001 | Handmade wooden chair with oak wood | 700 | 2.5 | 50
|
| 00200001 | Heart crochet | 150 | 0.2 | 0
|
| 00200002 | Decorative wall hanging made with beads | 199 | 0.75 | 0
|
PRODUCT IMAGES
| product_code | image
|
|---|
| 00100001 | chair.jpg
|
| 00200001 | crochet-heart-red.jpg
|
| 00200001 | crochet-heart-blue.jpg
|
| 00200002 | wall_hanging.jpg
|
ORDER
| order_num | clien_ID | status | payment | discount
|
|---|
| 0012025000001 | 2 | Delivered | Cash | 4
|
| 0022025000001 | 1 | Placed Order | Credit Card | 0
|
| 0022025000002 | 1 | Packaging | PayPal | 0
|
| 0012025000002 | 3 | Packaging | Credit Card | 5
|
| 0022025000003 | 1 | Placed Order | Credit Card | 2
|
ORDER PRODUCTS
| order_num | product_code | quantity
|
| 0012025000001 | 00100001 | 1
|
| 0022025000001 | 00200002 | 2
|
| 0022025000002 | 00200001 | 3
|
| 0012025000002 | 00100001 | 1
|
| 0012025000002 | 00200001 | 1
|
| 0022025000003 | 00200002 | 1
|
REVIEW
| order_num | rating | comment
|
|---|
| 0012025000001 | 4.0 | Great quality, slightly late delivery
|
| 0022025000001 | 5.0 | Excellent craftsmanship
|
| 0022025000002 | 5.0 | Beautiful handmade product
|
| 0012025000002 | 5.0 | Very satisfied
|
| 0022025000003 | 5.0 | Wonderful decoration
|
REQUEST
| request_num | client_ID | problem
|
|---|
| 001112025001 | 2 | Late delivery
|
| 002122025001 | 3 | Military discount
|
| 003122025001 | 3 | Packaging question
|
| 004122025001 | 1 | Shipping question
|
REPORT
| store_ID | date | overall_profit | monthly_profit | sales_trend
|
|---|
| 001 | 2024-11-30 | 125000 | 12500 | Increasing
|
| 002 | 2024-11-30 | 98000 | 8000 | Stable
|
Explanataion: UNF -> 1NF
The denormalized table violated First Normal Form because several attributes stored multiple values in a single cell. Examples include product colors, product images, multiple products in one order, and multiple stores associated with an order. These repeating groups made the data difficult to search, update, and maintain.
To convert the database into First Normal Form, all repeating groups were removed and each attribute was made atomic. Separate tables were created for product colors, product images, delivery addresses, order contents, and reviews. Each row now contains only one value for every attribute, eliminating multi-valued cells and ensuring that every record can be uniquely identified by a primary key.
Although the database is now in First Normal Form, redundancy still exists. For example, client information is repeated in the Order table, and product details are repeated whenever the same product appears in different orders. These partial dependencies will be removed when converting the schema to Second Normal Form (2NF).
A relation is in Second Normal Form (2NF) if:
1. It is already in First Normal Form (1NF).
2. Every non-key attribute is fully functionally dependent on the whole primary key.
3. There are no partial dependencies.
A partial dependency occurs when part of a composite primary key determines a non-key attribute.
CLIENT
| client_ID | first_name | last_name | email | password
|
|---|
| 1 | Ivan | Stojanov | ivan@… | HLUaguhoBJKbjhVjkgKJkjVHK
|
| 2 | Marija | Kostova | marija@… | CHVLKDNVJKnkjbkjbjkVKnkNkjbKJ
|
| 3 | Antoneta | Mariovska | mariovskaantoneta@… | KHkukUhukGUhIKLjLjgukguhLKhukFkHvbH
|
DELIVERY ADDRESS
| client_ID | address
|
|---|
| 1 | st.Partizanska 10, Skopje
|
| 2 | st.Turisticka 5, Bitola
|
| 3 | st.32 4, s.Cucer-Sandevo
|
STORE
| store_ID | name | date_founded | address | email | rating
|
|---|
| 001 | WoodCraft Skopje | 2015-03-12 | st.Ilindenska 45, Skopje | contact@… | 4.6
|
| 002 | Fox Crochets | 2023-06-01 | st.Kej Makedonija 12, Ohrid | ohrid@… | 4.8
|
PRODUCT
| product_code | price | availability | weight | dimensions | production_time | description | delivery_cost
|
|---|
| 00100001 | 700 | 50 | 2.5 | 30×20×10 | 10 | Handmade wooden chair with oak wood | 50
|
| 00200001 | 150 | 10 | 0.2 | 20×20×15 | 2 | Heart crochet | 0
|
| 00200002 | 199 | 100 | 0.75 | 40×40×1 | 14 | Decorative wall hanging made with beads | 0
|
IMAGE
| product_code | image
|
|---|
| 00100001 | chair.jpg
|
| 00200001 | crochet-heart-red.jpg
|
| 00200001 | crochet-heart-blue.jpg
|
| 00200002 | wall_hanging.jpg
|
COLOR
| product_code | color
|
|---|
| 00100001 | Brown
|
| 00200001 | Blue
|
| 00200001 | Red
|
| 00200001 | Yellow
|
| 00200001 | Green
|
| 00200002 | White & Pink
|
| 00200002 | Black & Gold
|
| 00200002 | Orange, Green & Purple
|
SELLS
| store_ID | product_code | discount
|
|---|
| 001 | 00100001 | 0
|
| 002 | 00200001 | 0
|
| 002 | 00200002 | 0.5
|
ORDER
| order_num | client_ID | status | last_modified | payment_method | discount
|
|---|
| 0012025000001 | 2 | Delivered | 2025-12-02 | Cash | 0.04
|
| 0022025000001 | 1 | Placed Order | 2025-12-01 | Credit Card | 0.00
|
| 0022025000002 | 1 | Packaging | 2025-12-10 | PayPal | 0.00
|
| 0012025000002 | 3 | Packaging | 2025-12-12 | Credit Card | 0.05
|
| 0022025000003 | 1 | Placed Order | 2025-12-15 | Credit Card | 0.02
|
INCLUDES
| order_num | product_code | quantity
|
|---|
| 0012025000001 | 00100001 | 1
|
| 0022025000001 | 00200002 | 2
|
| 0022025000002 | 00200001 | 3
|
| 0012025000002 | 00100001 | 1
|
| 0012025000002 | 00200001 | 1
|
| 0022025000003 | 00200002 | 1
|
REVIEW
| order_num | comment | rating | last_modified
|
|---|
| 0012025000001 | Great quality, slightly late delivery | 4 | 2024-12-05
|
| 0022025000001 | Excellent craftsmanship | 5 | 2025-12-03
|
| 0022025000002 | Beautiful handmade product | 5 | 2025-12-11
|
| 0012025000002 | Very satisfied | 5 | 2025-12-14
|
| 0022025000003 | Wonderful decoration | 5 | 2025-12-20
|
PERSONAL
| employee_SSN | first_name | last_name | email | password
|
|---|
| 1234567890123 | Marko | Petrovski | marko@… | BuHuhjgholko8u7T76TVYFgfChHBJHVGHh
|
| 9876543210987 | Antonio | Trajkovski | antonio@… | kgvhjgbJgfHGvHhbhg6777t%dcGfyR%G
|
| 4567891234567 | Sara | Vaneva | s.vaneva@… | UGUgt&ghjGFu6tgVfCTYt6VghyT6yvHJg
|
PERMISSIONS
| personal_SSN | type | authorization
|
|---|
| 1234567890123 | Boss | Admin
|
| 9876543210987 | Employee | M.Petrovski
|
| 4567891234567 | Boss | Admin
|
WORKS_IN_STORE
| personal_SSN | store_ID
|
|---|
| 1234567890123 | 001
|
| 9876543210987 | 001
|
| 4567891234567 | 002
|
WORKED
| personal_SSN | report_date | store_ID | wage | pay_method | hours | week
|
|---|
| 1234567890123 | 2025-11-30 | 001 | 75 | Hourly | 48 | 24–30 Nov
|
| 9876543210987 | 2025-11-30 | 001 | 75 | Hourly | 38 | 24–30 Nov
|
| 4567891234567 | 2025-11-30 | 002 | 450 | Weekly | 52 | 24–30 Nov
|
REPORT
| date | store_ID | overall_profit | sales_trend | marketing_growth | signature
|
|---|
| 2024-11-30 | 001 | 125000 | Increasing | Stable Growth | M.Petrovski
|
| 2024-11-30 | 002 | 98000 | Stable | Moderate Growth | S.Vaneva
|
MONTHLY_PROFIT
| report_date | store_ID | month | profit
|
|---|
| 2024-11-30 | 001 | Nov 2024 | 12500
|
| 2024-11-30 | 002 | Nov 2024 | 8000
|
REQUEST
| request_num | date | problem | notes | satisfaction
|
|---|
| 001112025001 | 2024-11-03 | Late delivery | Discount offered | 4
|
| 002122025001 | 2024-12-04 | Military discount | Approved | 5
|
| 003122025001 | 2024-12-10 | Packaging question | Explained shipping | 5
|
| 004122025001 | 2024-12-16 | Shipping question | Tracking provided | 5
|
MAKES REQUEST
| client_ID | request_num
|
|---|
| 2 | 001112025001
|
| 3 | 002122025001
|
| 3 | 003122025001
|
| 1 | 004122025001
|
ANSWERS
| client_ID | request_num
|
|---|
| 2 | 001112025001
|
| 3 | 002122025001
|
| 3 | 003122025001
|
| 1 | 004122025001
|
Explanation: 1NF -> 2NF
The First Normal Form removed repeating groups by ensuring that each attribute contained only atomic values. However, some relations still contained composite primary keys, creating the possibility of partial dependencies, where non-key attributes depended on only part of the key instead of the entire key.
For example, in the INCLUDES relation, the composite key is (Order_Number, Product_Code). Product attributes such as description, price, weight, and production time depend only on Product_Code, not on the entire composite key. These attributes were therefore moved into the separate PRODUCT table. Similarly, store-specific discounts were placed in the SELLS relation because the discount depends on the combination of a store and a product rather than on either entity alone.
The same principle was applied throughout the schema. Tables such as IMAGE, COLOR, WORKS_IN_STORE, WORKED, MAKES_REQUEST, and ANSWERS contain only attributes that depend on their complete composite keys. As a result, every non-key attribute in every relation is fully functionally dependent on the whole primary key, satisfying the requirements of Second Normal Form.
Despite these improvements, some transitive dependencies still remain. For instance, information such as employee roles and permissions, report approvals, and specialized employee types (Boss and Employee) can still be further separated. Removing these transitive dependencies leads to Third Normal Form (3NF), which will be covered in Part 3.
A relation is in Third Normal Form (3NF) if:
1. It is already in Second Normal Form (2NF).
2. There are no transitive dependencies.
3. Every non-key attribute depends only on the primary key, and not on another non-key attribute.
A transitive dependency occurs when:
Primary Key -> Non-key Attribute A
Non-key Attribute A -> Non-key Attribute B
which means
Primary Key → Non-key Attribute B
indirectly.
Example:
| employeeSSN | store_ID | store_name | store_address
|
|---|
If
Primary Key -> Non-key Attribute A
Non-key Attribute A -> Non-key Attribute B
then Store Name and Store Address should not be stored with Employee records. They belong in the STORE table.
3NF removes these remaining redundancies.
PERSONAL
Primary key: employee_SSN
| employee_SSN | first_name | last_name | email | password
|
|---|
| 1234567890123 | Marko | Petrovski | marko@… | BuHuhjgholko8u7T76TVYFgfChHBJHVGHh
|
| 9876543210987 | Antonio | Trajkovski | antonio@… | kgvhjgbJgfHGvHhbhg6777t%dcGfyR%G
|
| 4567891234567 | Sara | Vaneva | s.vaneva@… | UGUgt&ghjGFu6tgVfCTYt6VghyT6yvHJg
|
PERMISSIONS
Primary key: employee_SSN
Forgein key: employee_SSN -> PERSONAL
| personal_SSN | type | authorization
|
|---|
| 1234567890123 | Boss | Admin
|
| 9876543210987 | Employee | M.Petrovski
|
| 4567891234567 | Boss | Admin
|
BOSS
Primary key: boss_SSN
Forgein key: boss_SSN -> PERSONAL(employee_SSN)
| boss_SSN
|
|---|
| 1234567890123
|
| 4567891234567
|
EMPLOYEE
Primary key: employee_SSN
Forgein key: employee_SSN -> PERSONAL
| employee_SSN | date_of_hire
|
|---|
| 9876543210987 | 2019-09-01
|
STORE
| store_ID | name | date_founded | address | email | rating
|
|---|
| 001 | WoodCraft Skopje | 2015-03-12 | st.Ilindenska 45, Skopje | contact@… | 4.6
|
| 002 | Fox Crochets | 2023-06-01 | st.Kej Makedonija 12, Ohrid | ohrid@… | 4.8
|
WORKS_IN_STORE
| personal_SSN | store_ID
|
|---|
| 1234567890123 | 001
|
| 9876543210987 | 001
|
| 4567891234567 | 002
|
PRODUCT
| product_code | price | availability | weight | dimensions | production_time | description | delivery_cost
|
|---|
| 00100001 | 700 | 50 | 2.5 | 30×20×10 | 10 | Handmade wooden chair with oak wood | 50
|
| 00200001 | 150 | 10 | 0.2 | 20×20×15 | 2 | Heart crochet | 0
|
| 00200002 | 199 | 100 | 0.75 | 40×40×1 | 14 | Decorative wall hanging made with beads | 0
|
IMAGE
| product_code | image
|
|---|
| 00100001 | chair.jpg
|
| 00200001 | crochet-heart-red.jpg
|
| 00200001 | crochet-heart-blue.jpg
|
| 00200002 | wall_hanging.jpg
|
COLOR
| product_code | color
|
|---|
| 00100001 | Brown
|
| 00200001 | Blue
|
| 00200001 | Red
|
| 00200001 | Yellow
|
| 00200001 | Green
|
| 00200002 | White & Pink
|
| 00200002 | Black & Gold
|
| 00200002 | Orange, Green & Purple
|
SELLS
| store_ID | product_code | discount
|
|---|
| 001 | 00100001 | 0
|
| 002 | 00200001 | 0
|
| 002 | 00200002 | 0.5
|
CLIENT
| client_ID | first_name | last_name | email | password
|
|---|
| 1 | Ivan | Stojanov | ivan@… | HLUaguhoBJKbjhVjkgKJkjVHK
|
| 2 | Marija | Kostova | marija@… | CHVLKDNVJKnkjbkjbjkVKnkNkjbKJ
|
| 3 | Antoneta | Mariovska | mariovskaantoneta@… | KHkukUhukGUhIKLjLjgukguhLKhukFkHvbH
|
DELIVERY ADDRESS
| client_ID | address
|
|---|
| 1 | st.Partizanska 10, Skopje
|
| 2 | st.Turisticka 5, Bitola
|
| 3 | st.32 4, s.Cucer-Sandevo
|
ORDER
| order_num | client_ID | status | last_modified | payment_method | discount
|
|---|
| 0012025000001 | 2 | Delivered | 2025-12-02 | Cash | 0.04
|
| 0022025000001 | 1 | Placed Order | 2025-12-01 | Credit Card | 0.00
|
| 0022025000002 | 1 | Packaging | 2025-12-10 | PayPal | 0.00
|
| 0012025000002 | 3 | Packaging | 2025-12-12 | Credit Card | 0.05
|
| 0022025000003 | 1 | Placed Order | 2025-12-15 | Credit Card | 0.02
|
INCLUDES
| order_num | product_code
|
|---|
| 0012025000001 | 00100001
|
| 0022025000001 | 00200002
|
| 0022025000002 | 00200001
|
| 0012025000002 | 00100001
|
| 0012025000002 | 00200001
|
| 0022025000003 | 00200002
|
REVIEW
| order_num | comment | rating | last_modified
|
|---|
| 0012025000001 | Great quality, slightly late delivery | 4 | 2024-12-05
|
| 0022025000001 | Excellent craftsmanship | 5 | 2025-12-03
|
| 0022025000002 | Beautiful handmade product | 5 | 2025-12-11
|
| 0012025000002 | Very satisfied | 5 | 2025-12-14
|
| 0022025000003 | Wonderful decoration | 5 | 2025-12-20
|
REQUEST
| request_num | date | problem | notes | satisfaction
|
|---|
| 001112025001 | 2024-11-03 | Late delivery | Discount offered | 4
|
| 002122025001 | 2024-12-04 | Military discount | Approved | 5
|
| 003122025001 | 2024-12-10 | Packaging question | Explained shipping | 5
|
| 004122025001 | 2024-12-16 | Shipping question | Tracking provided | 5
|
MAKES REQUEST
| client_ID | request_num
|
|---|
| 2 | 001112025001
|
| 3 | 002122025001
|
| 3 | 003122025001
|
| 1 | 004122025001
|
ANSWERS
| client_ID | request_num
|
|---|
| 2 | 001112025001
|
| 3 | 002122025001
|
| 3 | 003122025001
|
| 1 | 004122025001
|
REQUEST_FOR_STORE
| request_number | store_ID
|
|---|
| 001112025001 | 001
|
| 002122025001 | 002
|
Instead of storing store information inside REQUEST, a relationship table is used.
REPORT
| date | store_ID | overall_profit | sales_trend | marketing_growth | signature
|
|---|
| 2024-11-30 | 001 | 125000 | Increasing | Stable Growth | M.Petrovski
|
| 2024-11-30 | 002 | 98000 | Stable | Moderate Growth | S.Vaneva
|
MONTHLY_PROFIT
| report_date | store_ID | month | profit
|
|---|
| 2024-11-30 | 001 | Nov 2024 | 12500
|
| 2024-11-30 | 002 | Nov 2024 | 8000
|
WORKED
| personal_SSN | report_date | store_ID | wage | pay_method | hours | week
|
|---|
| 1234567890123 | 2025-11-30 | 001 | 75 | Hourly | 48 | 24–30 Nov
|
| 9876543210987 | 2025-11-30 | 001 | 75 | Hourly | 38 | 24–30 Nov
|
| 4567891234567 | 2025-11-30 | 002 | 450 | Weekly | 52 | 24–30 Nov
|
APPROVES
| boss_SSN | report_date | store_ID | signature
|
|---|
| 1234567890123 | 2025-12-01 | 001 | M.Petrovski
|
| 4567891234567 | 2025-12-03 | 002 | S.Vaneva
|
The approval relationship is separated from the report because a report is approved by a boss, and this relationship should not duplicate boss information.
STORE_MONTHLY_DATA
| report_date | store_ID | monthly_profit | date | sales | samages |
|
|---|
| 2024-11-30 | 001 | 38750 | 2024-12-01 | 52 | 750
|
| 2024-11-30 | 002 | 26150 | 2024-12-01 | 40 | NULL
|
Explanation: 2NF -> 3NF
Although the database satisfied Second Normal Form by eliminating partial dependencies, some transitive dependencies still existed. In Third Normal Form, these remaining dependencies were removed by ensuring that every non-key attribute depends directly and only on the primary key.
For example, employee role information was separated from the PERSONAL table into the PERMISSIONS relation, while employee specializations were represented by the BOSS and EMPLOYEE tables. This prevents storing attributes that apply only to certain personnel in every employee record. Likewise, relationships such as WORKS_IN_STORE, APPROVES, FOR_STORE, MAKES_REQUEST, and ANSWERS isolate many-to-many associations into dedicated tables instead of embedding foreign entity information in other relations.
The PRODUCT, STORE, CLIENT, and ORDER tables now contain only attributes that describe their own entities. Information about colors, images, delivery addresses, reviews, reports, monthly profits, and request handling is stored in separate relations connected through foreign keys. This design eliminates update, insertion, and deletion anomalies and greatly reduces data redundancy.
The resulting schema is fully normalized to Third Normal Form, where each relation represents a single entity or relationship, each non-key attribute depends only on its table's primary key, and all associations between entities are maintained through foreign keys.
Summary of Normalization process
| Normal Form | Main Objective | Changes Made
|
|---|
| Denormalized (UNF) | Store all data in one large table | Repeating groups and multi-valued attributes exist, leading to redundancy and anomalies.
|
| First Normal Form (1NF) | Eliminate repeating groups and ensure atomic values | Multi-valued attributes (e.g., colors, images, products in an order) are split into separate rows or relations so that each field contains a single value.
|
| Second Normal Form (2NF) | Remove partial dependencies | Attributes that depend on only part of a composite key are moved to separate tables (e.g., product details, store details). Relationship tables retain only attributes dependent on the full composite key.
|
| Third Normal Form (3NF) | Remove transitive dependencies | Attributes that depend on other non-key attributes are separated into dedicated relations (e.g., permissions, employee roles, report approvals, request handling), leaving each table to describe a single entity or relationship.
|
