Normalization

There are several levels of normalization, each with its own set of rules and guidelines. The most common levels of normalization are:

1. First Normal Form (1NF): In 1NF, each table has a primary key, and every column in the table contains atomic values. This means that each column should contain only one value rather than a list or collection of values.

2. Second Normal Form (2NF): In 2NF, the table is in 1NF, and every non-key column in the table is dependent on the primary key. This means that each non-key column in the table should be related to the primary key in a meaningful way.

3. Third Normal Form (3NF): In 3NF, the table is in 2NF, and every non-key column in the table is independent of every other non-key column. This means that each non-key column in the table should be related only to the primary key and not to any other non-key column.

There are additional levels of normalization, including Boyce-Codd Normal Form (BCNF) and Fourth Normal Form (4NF), which build upon the previous levels and provide even further optimization of the database.

The benefits of database normalization include improved data consistency, reduced data redundancy, and easier maintenance of the database. By reducing data redundancy, normalization also helps to ensure that updates to the database are made consistently and accurately across all relevant tables.

Overall, database normalization is an important process for ensuring that a database is well-organized and optimized for efficient data storage and retrieval.

• Normalization is a process for evaluating and correcting table structures to minimize data redundancies.

  • It reduces the likelihood of data anomalies

  • Assigns attributes to tables based on determination

• Normalization works through a series of stages called normal forms and the first three are described as follows:

  • First normal form (1NF)

  • Second normal form (2NF)

  • Third normal form (3NF)

• From a structural point of view, higher normal forms are better than lower normal forms

  • For most purposes in business database design, 3NF is as high as you need to go in the normalization process

The Need for Normalization

• Database designers commonly use normalization in the following two situations:

  • When designing a new database structure

  • To analyze the relationship among the attributes within each entity and determine if the structure can be improved through normalization

• The main goal of normalization is to eliminate data anomalies by eliminating unnecessary or unwanted data redundancies.

• Normalization uses the concept of functional dependencies to identify which attribute determines other attributes

Denormalization

• From a structural point of view, higher normal forms are better than lower normal forms

  • For most purposes in business database design, 3NF is as high as you need to go in the normalization process

• Denormalization produces a lower normal form

  • The result of denormalization is increased performance but greater data redundancy