What is normalization and types of normalization?

Answer Posted / udhaya kumar

Normal forms in SQL are given below.

First Normal form (1NF): A relation is said to be in 1NF if
it has only single valued attributes, neither repeating nor
arrays are permitted.

Second Normal Form (2NF): A relation is said to be in 2NF if
it is in 1NF and every non key attribute is fully functional
dependent on the primary
key.

Third Normal Form (3NF): We say that a relation is in 3NF if
it is in 2NF and has no transitive dependencies.

Boyce-Codd Normal Form (BCNF): A relation is said to be in
BCNF if and only if every determinant in the relation is a
candidate key.

Fourth Normal Form (4NF): A relation is said to be in 4NF if
it is in BCNF and contains no multi valued attributes.

Fifth Normal Form (5NF): A relation is said to be in 5NF if
and only if every join dependency in relation is implied by
the candidate keys of relation.

Domain-Key Normal Form (DKNF): We say that a relation is in
DKNF if it is free of all modification anomalies. Insertion,
Deletion, and update anomalies come under modification
anomalies.
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