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Sixth Normal Form (6NF)
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.
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