Relational database design Normalization Types of Normalization 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.