Normalization of Relational Database

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Normalization is the process of organizing data in a relational database to reduce redundancy and dependency, improve data integrity, and optimize database performance. It involves breaking down large tables into smaller, more manageable structures and establishing relationships between them. There are several normal forms (1NF, 2NF, 3NF, BCNF, 4NF, 5NF) that represent different levels of normalization, each with its own set of rules and requirements. Here's an overview of the normalization process:

1.First Normal Form (1NF):
  • Eliminate repeating groups: Ensure that each column in a table contains atomic values (values are indivisible).
  • Identify a primary key: Choose a unique identifier for each row in the table.
2.Second Normal Form (2NF):

  • Meet the requirements of 1NF.
  • Remove partial dependencies: Ensure that each non-key attribute is fully functionally dependent on the primary key. If necessary, move attributes that depend on only part of the primary key to a separate table.

3.Third Normal Form (3NF):

  • Meet the requirements of 2NF.
  • Remove transitive dependencies: Ensure that non-key attributes are not transitively dependent on the primary key through other non-key attributes. If necessary, move dependent attributes to separate tables.

4.Boyce-Codd Normal Form (BCNF):

  • Meet the requirements of 3NF.
  • Eliminate all non-trivial functional dependencies where the determinant is a candidate key.

5.Fourth Normal Form (4NF):

  • Meet the requirements of BCNF.
  • Remove multi-valued dependencies: Ensure that each non-key attribute is fully functionally dependent on the primary key, and no non-key attribute is dependent on another non-key attribute.

6.Fifth Normal Form (5NF):

  • Meet the requirements of 4NF.
  • Eliminate join dependencies: Ensure that all join dependencies are implied by candidate keys.

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