Normalization is a technique for organizing data in databases to eliminate redundancy and undesirable characteristics like insertion, update, and deletion anomalies. It involves decomposing tables and removing duplicated data to put it into tabular form. The goals of normalization are to eliminate redundant data and ensure data dependencies make logical sense. There are three common forms of normalization: first normal form eliminates repeating groups of attributes; second normal form prevents non-key attributes from depending on only part of a primary key; and third normal form removes non-key attributes that depend on other non-key attributes.

1. Normalizati
on

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⊷ Group Members
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1. P.P.P.Madhushani
2. G.G.A.R.U.Gunasekara
3. N.H.B.Pethiyagoda
4. Ayesha Vidyani

3. Normalization
⊷ Database Normalization is a technique of organizing
the data in the database. Normalization is a systematic
approach of decomposing tables to eliminate data
redundancy(repetition) and undesirable characteristics
like Insertion, Update and Deletion Anamolies. It is a
multi-step process that puts data into tabular form,
removing duplicated data from the relation tables.
Normalization is used for mainly two purposes,
⊷ Eliminating redundant (useless) data.
⊷ Ensuring data dependencies make sense i.e. data is
logically stored.
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Data Redundancy occurs when the same data is entered
in to two or more fields of a database.
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Difference Between Duplication and Redundancy
Data Duplication occurs when an exact copy of a
piece of data is created.

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Aims of Normalization

6. Problems
Without
Normalization
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7. There are 3 problems
that can occur without
Normalization
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⊷ 1. Insert Anomaly
⊷ 2. Delete Anomaly
⊷ 3. Update Anomaly

8. Stages of Normalization
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⊷ First Normal Form
⊷ Second Normal Form
⊷ Third Normal Form
⊷ BCNF
⊷ Fourth Normal Form

9. First Normal Form
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A table is in it’s first normal form if
it contains no repeating attributes
or groups of attributes.

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12. Second Normal Form
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A table is in the second normal
form AND no column that is not
part of the primary key is
dependant only a portion of the
Primary Key.

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15. Third Normal Form
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A table is in the third normal
form if it is in the second
normal form. And there are
no non-key columns
dependant on other non-key
columns that could not act
as the primary key.

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18. Thank You
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