How to Achieve Fourth Normal Form (4NF) in Database Design
Getting your database to Fourth Normal Form, or 4NF, takes careful planning. It mainly focuses on getting rid of multi-valued dependencies. Here are some simple steps you can follow:
Start with a 3NF Design
First, make sure your database is already at Third Normal Form (3NF). This means it should not have any unwanted dependencies and should only contain simple, single values.
Look for Multi-Valued Dependencies
Check your tables to see if there are any attributes that depend on another attribute, but not on the whole primary key.
For example, if one course can have several instructors and several textbooks, that’s a multi-valued dependency.
Make Separate Tables
To fix the multi-valued dependencies you found, you need to create separate tables. Each new table should have just one multi-valued attribute.
For example, you might make one table for courses and their instructors, and another for courses and their textbooks.
Set Up Relationships
After you’ve split the attributes into their own tables, go ahead and define foreign keys. These keys help connect the separate tables to each other.
This keeps everything in your database organized and linked correctly.
Review and Adjust
Lastly, take a good look at your entire database design again. Make sure that all the new tables meet the rules for 4NF and don’t create any new problems.
By following these steps, you can reach Fourth Normal Form in your university database. This will help you create a strong design that cuts down on unnecessary data and keeps your information accurate.
How to Achieve Fourth Normal Form (4NF) in Database Design
Getting your database to Fourth Normal Form, or 4NF, takes careful planning. It mainly focuses on getting rid of multi-valued dependencies. Here are some simple steps you can follow:
Start with a 3NF Design
First, make sure your database is already at Third Normal Form (3NF). This means it should not have any unwanted dependencies and should only contain simple, single values.
Look for Multi-Valued Dependencies
Check your tables to see if there are any attributes that depend on another attribute, but not on the whole primary key.
For example, if one course can have several instructors and several textbooks, that’s a multi-valued dependency.
Make Separate Tables
To fix the multi-valued dependencies you found, you need to create separate tables. Each new table should have just one multi-valued attribute.
For example, you might make one table for courses and their instructors, and another for courses and their textbooks.
Set Up Relationships
After you’ve split the attributes into their own tables, go ahead and define foreign keys. These keys help connect the separate tables to each other.
This keeps everything in your database organized and linked correctly.
Review and Adjust
Lastly, take a good look at your entire database design again. Make sure that all the new tables meet the rules for 4NF and don’t create any new problems.
By following these steps, you can reach Fourth Normal Form in your university database. This will help you create a strong design that cuts down on unnecessary data and keeps your information accurate.