What is normalization and what are normalization forms?

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Normalization is a technique that decomposes the table to reduce the redundacy of data.

There are 3 normalization forms we need to check and follow to normalize tables.

  • Each coloum of the table should have a single value
  • Each column should belong to a same domain
  • Two colums should not have a same name
  • It need not to be a proper order, e.g., we need not to sort the records according to the date of DOB.
  • The table should be satisfy 1st Normalization Form
  • All the non-key attributes myst be functionally dependently on primary key
  • The table should be satisfy 2nd Normalization Form
  • There is no transitive dependency for non-prime attributes

The transitive functional dependency is as follows:

A is functional dependent on B and B is functional dependent on C. So, C is transitive dependent on A through B.

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Originally published at http://jacquiwu.com on March 11, 2020.

Written by

A current Data Analyst in a subsidiary under Webjet, with experience in applying data science techniques to business.

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