Sixth Normal Form (6NF)

RDBMSDatabaseMySQL

In 6NF, the relation variable is decomposed into irreducible components. A relation is in 6NF, only if, It is in 5NF, and every join dependency on the relation is trivial

Let us see an example −

<Student>

Enrollment_No
Name
Marks


The possible join dependencies for the above would be −

{Enrollment_No, Marks}
{Enrollment_No, Name}


In Sixth Normal Form (6NF), it would be decomposed to −

<StudentInformation>

Enrollment_No
Name


<ResultInformation>

Enrollment_No
 Marks


Let us see another example −

<StudentMarks>

Student_ID
Student_FirstName
Student_LastName
Marks
S01
Tom
Alter
90
S02
Jacob
Watson
80
S03
Harry
Smith
85


Let us decompose the table −

<StudentFirstName>

Student_ID
Student_FirstName
S01
Tom
S02
Jacob
S03
Harry


<StudentLastName>

Student_ID
Student_LastName
S01
Alter
S02
Watson
S03
Smith


<StudentResult>

Student_ID
Marks
S01
90
S02
80
                     S03
                   85


Now the above tables are in 6NF, but as you can guess on your know that this isn’t possible in real-world.

raja
Published on 04-Jul-2018 14:09:03
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