Page 152 - DCAP402_DCAO204_DATABASE MANAGEMENT SYSTEM_MANAGING DATABASE

Unit 8: Normalization

8.9 Keywords Notes

Boyce-Codd Normal Form: A relation is in Boyce-Codd Normal Form (BCNF) if and only if
every determinant in the relation is a candidate key.

Non Key Attribute: A non-key attribute is fully functionally dependent on the primary key if it
is functionally dependent on all the attributes comprising the primary key.
Normalization: Normalization consists of a series of rules that should be employed to make
sure that the table is fully normalized by listing the functional dependencies and decomposing
it into smaller, efficient tables.
Transitive Dependency: A transitive dependency arises when a non-key column is functionally
dependent on another non-key column that in turn is functionally dependent on the primary
key.

8.10 Self Assessment

Fill in the blanks:
1. The fifth normal form deals with join-dependencies, which is a generalisation of the
...........................................
2. Normalization is the process of refining the design of relational tables to minimize data
...........................................

3. ........................................... is based on the concept of normal forms.
4. The Third normal form resolves ........................................... dependencies.
5. A ........................................... arises when a non-key column is functionally dependent on
another non-key column that in turn is functionally dependent on the primary key.
6. ........................................... provide a method for maintaining integrity in the data.
7. A ........................................... dependency occurs when in a relational table containing at
least three columns.
8. The ........................................... form is usually applied only for large relational data models.
9. Normal forms are table structures with ...........................................

10. Normalization eliminates data maintenance anomalies, minimizes redundancy, and
eliminates ...........................................

8.11 Review Questions

1. Sketch with examples the differences between the Third Normal Form (3NF) and Boyce
Codd Normal Form.
2. Explain the disadvantage of normalization.
3. Give a relation which is in 2 NF but not in 3 NF.

4. "Normalization is the process of refining the design of relational tables to minimize data
redundancy". Explain
5. "A relation R is said to be in the first normal form (1NF) if and only if every attribute
contains atomic values only". Discuss with the help of suitable example.

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