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Normalisation of Databases

Normalisation is a process that we go through when we are desigining a database to ensure that a database has the right or most efficient structure.

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For a database to be normalised, it must go through various "forms" or stages.

The forms are progressive, meaning that to qualify for 3rd normal form a table must first satisfy the rules for 2nd normal form, and 2nd normal form must adhere to those for 1st normal form. Before we discuss the various forms and rules in detail, let’s summarize the various forms:

Normal Forms

First Normal Form – The information is stored in a relational table with each column containing atomic values. There are no repeating groups of columns.
Second Normal Form – The table is in first normal form and all the columns depend on the table’s primary key.
Third Normal Form – the table is in second normal form and all of its columns are not transitively dependent on the primary key

There are additional normal forms but once a database gets to third normal form it is in pretty good shape!

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