Normalization is a database design technique that organizes tables to reduce redundancy and dependency of data. It addresses issues like insert, update, and deletion anomalies by separating normalized tables and defining relationships between them. The document discusses three normal forms - 1NF, 2NF, and 3NF - which have specific rules around single values in each cell, primary keys, and eliminating transitive dependencies.

1. Normalization
Normalization is a database design technique which
organizes tables in a manner that reduces redundancy and
dependency of data.

2. Reasons for Normalization
Insert Anomaly:
In our example we cannot record a new sales office until
we also know the sales person. Why? Because in order to
create the record, we need provide a primary key. In our
case this is the EmployeeID.
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3. Reasons for Normalization
Update Anomaly:
The same information is recorded in multiple rows. For
instance if the office number changes, then there are multiple
updates that need to be made. If these updates are not
successfully completed across all rows, then an inconsistency
occurs.
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4. Reasons for Normalization
Deletion Anomaly:
Deletion of a row can cause more than one set of facts to
be removed. For instance, if John Hunt retires, then
deleting that row cause use to lose information about the
New York office.
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5. Normalization Rule
Database Normal Forms:
 1NF (First Normal Form) Rules
oEach table cell should contain single value.
oEach record needs to be unique
oNo rows of data should have repeating group of column values
 2NF (Second Normal Form) Rules
oRule 1- Be in 1NF
oRule 2- Single Column Primary Key
 3NF (Third Normal Form) Rules
oRule 1- Be in 2NF
oRule 2- Has no transitive functional dependencies
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6. First Normal Form(1NF)
Repeated groups
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7. Second Normal Form(2NF)
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8. Third Normal Form(3NF)
 Let’s add three more columns - STREET, CITY and ZIP to
STUDENT table to explain 3NF
 simplest to think of transitive dependence to mean a column’s
value relies upon another column through a second intermediate
column
STUDENT ZIP CITY
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9. Third Normal Form(3NF)

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