Relational Database and Normalization
Second Normal Form
The Second Normal Form Rules:
- Requires the First Normal Form.
- The data that repeatedly appear in several rows should be presented in separate tables.
Look at the example:
Here we can see that John, Ivan, and Platon work in one company named Good Job Corporation.
So, let's normalize it! The second normal form:
Now the database has not a duplicate of information about the country of the company. Now it takes up less memory.
Summary. Second Normal Form
|Takes up less memory|
|Improves the structure of the database|
What mean the Second Normal Form?
Select a few correct answers