What is Normalization in SQL ?

SQL

Normalization is used to decompose a larger, complex table into simple and smaller ones. This helps us in removing all the redundant data. Generally, in a table, we will have a lot of redundant information which is not required, so it is better to divide this complex table into multiple smaller tables which contains only unique information. First normal form: A relation schema is in 1NF, if and only if : – All attributes in the relation are atomic(indivisible value) - And there are no repeating elements or group of elements. Second normal form: A relation is said to be in 2NF, if and only if: It is in 1st Normal Form. No partial dependency exists between non-key attributes and key attributes. Third Normal form: • A relation R is said to be in 3NF if and only if: It is in 2NF.

No transitive dependency exists between non-key attributes and key attributes through another non-key attribute

       

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