This document discusses relational database design. It defines relational databases as collections of tables with rows and columns. Each row represents a record and each column represents an attribute. The goals of relational database design are to store information without redundancy and retrieve it easily. Normalization is described as organizing data to reduce redundancy and improve integrity. The benefits of normalization include avoiding duplicate data and null values. Types of normalization discussed include first normal form, second normal form, third normal form, and Boyce-Codd normal form.

1. • Paper Name -- Database System
• Staff -- Ms. D. Saritha M.C.A., M.phil.,
• Class -- II Year
• Semester -- IV
• Unit -- V
• Topic -- Relational Database Design

2. RELATIONAL
DATABASE DESIGN

3. RELATIONAL DATABASE DESIGN
Relational database design:
The Relational database design is a
collection of tables , each of which
is assigned a unique name.
The table contain rows and
columns.
 Each row represents a record.
 Each column represents an
attribute of data.

4. RELATIONAL DATABASE DESIGN
Goal of Relational Database Design:
To generate a set of relation
schemas that allows as to store
information without unnecessary
redundancy,
It also retrieve information easily.
Normalization:
Normalization is organizing a
database to reduce redundancy
and improve data integrity.

5. In normalization, the elements
cannot be broken in small parts.
It is an important part of relational
database design.
It is also reffered to as database
normalization or data
normalization
Normalization helps speed,
accuracy and efficiency of the
database.

6. RELATIONAL DATABASE DESIGN
Benefits of Normalization:
It avoids the duplicate data.
It minimizes the null values.
It avoids data modification
issues
Normalization can simplifies
queries.

7. Types of Normalization:
The types of normalization are,
First Normal Form(1NF)
Second Normal Form(2NF)
Third Normal Form(3NF)
Boyce-Codd Normal
Form(BCNF)

8. First Normal Form(1NF):
First normal form sets the
fundamental rules for database
normalization and relates to a single
table within a relatioanal database
system.
Every column in the table must be
unique.
The separate tables must be created
for each set of related data.

9. Each table must be identified with a
unique column called the primary key.
The rows and columns cannot be
duplicated.
The intersection of rows and
columns(each cell)of the table must
have only a single value.
Second Normal Form(2NF):
It should be table is in the first normal
form.
There should be no partial
dependency.

10. Third Normal Form(3NF):
The third normal form relaxes this
constraint slightly by allowing
certain non trivial functional
dependencies whose left side is not
a super key.
A relation schema R is in third
normal form with respect to a set F
of functional dependencies if, for
all functional dependencies in F+ of
the form α→β

11. α→β is a trivial functional
dependency.
α is a superkey for β
Every attribute A in β- α is contained
in a candidate key for R.
Boyce-Codd Normal Form:
It avoids all redundancy that can be
discovered based on functional
dependencies.
α→β is a trivial functional
dependency.
α is a superkey for R.