What is normalization? Explain different levels of
normalization?
Answer Posted / vikram
The task of a database designer is to structure the data in
a way that eliminates unnecessary duplication and provides a
rapid search path to all necessary information. The process
of refining tables, keys, columns, and relationships to
create an efficient database is called normalization
because there is no redundant, neglected data and normalized
tables produce rapid, efficient joins.
There are 5 different normalization methods.
First Normal Form (1NF): Each field in a table must contain
different information.
Second Normal Form (2NF): All attributes that are not
dependent upon the primary key in a database table must be
eliminated.
Third Normal Form (3NF): No duplicate information is
permitted. So, for example, if two tables both require a
common field, this common field information should be
separated into a different table.
There are 2 more normalization forms, fourth normal form
(4NF) and fifth normal form (5NF), but they are rarely used.
Normalization makes databases more efficient and easier to
maintain.
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