RelationalDBDesign
RelationalDBDesign

Third Normal Form
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## Third normal form Conclusion

### Codd's 12 Criteria

### Glossary terms

### Third Normal Form - Quiz

Lesson 10

This module covered database normalization up to 3NF, explained how normalizing a database to 3NF meets Codd's 12 criteria for a fully relational database, noted there are normal forms beyond 3NF, and discussed denormalization.

Having completed this module, you should be able to:

Having completed this module, you should be able to:

- Explain the requirements for
*third normal form (3NF*) - Identify
*transitive dependencies* - Normalize a relation to 3NF
- Describe Codd's 12 criteria for a fully relational RDBMS
- Explain how Codd's 12 criteria relate to normalization
- Explain what type of dependencies might require normalization beyond 3NF
- Define denormalization and identify when it might be useful

This module introduced you to the following terms:

*third normal form (3NF):*A table is in third normal form if it contains no transitive dependencies.*denormalization:*To move a table to a lower normal form (e.g., from 3NF to 2NF).*determinant:*An attribute upon which another attribute is functionally dependent.*functional dependency:*A one-way relationship between two attributes so that, for any unique value of one attribute, there is only one value of the other attribute.*third normal form (3NF):*A table is in third normal form if it contains no transitive dependencies.*transitive dependency:*A term derived from the mathematical equation for a transitive property: If a>b and b>c, then a>c. In terms of a database, a transitive dependency refers to a relationship between two entities that is dependent upon a second relationship between one of the first two entities and a third entity.*transitivity:*Amathematical property which states that if A

- normalization to 3NF,
- Codd's rules,
- normalization beyond 3NF, and
- denormalization.

Before you continue to the next module, click the Quiz link below to reinforce your understanding of Third Normal Form - Quiz