Thursday, December 13, 2007

Explain normalization?

The normalization process involves getting our data to conform to three progressive normal forms

First Normal Form
The First Normal Form (or 1NF) involves removal of redundant data from horizontal rows. We want to ensure that there is no duplication of data in a given row, and that every column stores the least amount of information possible (making the field atomic).

Second Normal Form
Where the First Normal Form deals with redundancy of data across a horizontal row, Second Normal Form (or 2NF) deals with redundancy of data in vertical columns. As stated earlier, the normal forms are progressive, so to achieve Second Normal Form, your tables must already be in First Normal Form.

Third Normal Form
In Third Normal Form we are looking for data in our tables that is not fully dependant on the primary key, but dependant on another value in the table

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