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Relational Database Analysis

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Relational database normalization is the process of decomposing relations with anomalies to produce well structured relations. This paper delves into relational database normalization giving the reason why a database schema in third normal form is considered to be of higher quality than an un-normalized database schema.
Relational database normalization entails organizing database and it includes the creation of tables as well as relationships establishment between the tables using designed rules intended to protect the data as well as make the database to be flexible. This is achieved through the elimination of redundancy as well as inconsistent dependency. Redundant data is known to waste the space of the disk thereby creating problems of …show more content…

It also helps in maintaining data consistency in the database. The purpose of normalization is therefore to avoid redundancy by storing each fact within the database only once, to put data into the form that is more able to accurately accommodate change, to avoid certain updating anomalies, to facilitate the enforcement of data constraint and to avoid unnecessary coding. Extra programming in triggers stored procedures can be required to handle the non-normalized data and in turn can impair performance significantly (Davidson & Moss, 2012).
The degree of normalization is defined by normal forms. The forms in an increasing level of normalization include first normal form (1NF), second normal form (2NF), third normal form (3NF), Boyce-Codd normal form, Fourth normal form (4NF) and fifth normal form (5NF).Each normal form is a set of conditions on schema that guarantees certain properties relating to redundancy and update anomalies. In certain instances of lower level of normalization, queries take time to execute (Colomb, …show more content…

In this second normal form level, deficiencies which are transitive are removed. Third normal form satisfies the condition which requires that the relation to be in the second normal form. Another condition that it full is that it must not have transitive dependencies within the relations in the database. Transitive dependency occurs if an attribute is found to be functionally dependent on the key in an indirect manner. In this level, remaining functional dependency anomalies is removed. Boyce-Codd Normal requires that the relation to be in third normal form and that every determinant is supposed to be a candidate key. In this level, multi-valued dependencies are removed. A relation is in fourth normal form is it has a composite key and its key attributes have no multi-valued dependencies. In the fourth normal form, the remaining anomalies are removed. Fifth normal form is a generalization of the fourth normal form. It states that if a relation can be decomposed into the lossless join of several relations, then it should be so decomposed. The fifth normal form concerns dependencies that are obscure (Colomb, R. (2003)
A database schema in third normal form is considered to be of higher quality than an un-normalized database schema because the third normal form ensures that

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