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Tuesday, March 19, 2013

What is Normalization?


Normalization is the process of efficiently organizing data in a database. There are two goals of the normalizaton process:

Eliminating redundant data.
Ensuring data dependencies.

First Normal Form
First Normal form(1 NF) sets the very basic rules for an organized database.
  • Eliminate duplicative columns from the same table
  • Create seperate tables for each group of related data and identify each row with a unique column or set of columns(the promary key)

Second Normal Form
Second Normal form(2 NF) further addresses the concept of removing duplicative data.
  • Meet all the requirements of teh first normal form.
  • Remove subsets of data that apply to multiple rows of a table and place them in seperate tables.
  • Create relationships between these new tables and their predecessors through the use of foreign keys.

Third Normal Form
Third Normal form(3 NF) remove columns which are not dependent upon the primary key.
  • Meet all the requirements of the second normal form.
  • Remove columns that are not dependent upon the primary key.

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