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Explain normalization concept?
PHP Interview Questions and Answers
(Continued from previous question...)
Explain normalization concept?
The normalization process involves getting our data to conform to three progressive normal forms, and a higher level of normalization
cannot be achieved until the previous levels have been achieved (there are actually five normal forms, but the last two are mainly
academic and will not be discussed).
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
I have a confession to make; I do not often use 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
(Continued on next question...)
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