Una metodologia para para diseñar relaciones normalizadas

An Ameliorated Methodology to Design Normalized Relations
Ajeet A. Chikkamannur
Department of Computer Science and Engg.
REVA Institute of Technology & Mgmt.
Bangalore 560064 India
ac.ajeet@ gmail.com

Dr. Shivanand M. Handigund
Department of Computer Science and Engg.
Bangalore Institute of Technology
Bangalore 560004 India
smhandigund@gmail.com

Abstract

attributes that areinvolved in the minimally covered
set of functional dependencies to form relations.
Further, in pursuance of Boyce-Codd normal (BCNF),
the methodology refines them authenticating the
correctness and completeness of the software
requirements specification (SRS).

In Database design, the attributes and their
functional dependencies are abstracted from the
software requirements specification(SRS) by the
forward engineering process. The abstracted attributes
from a forward engineering process are structured
depending on the functional requirements. Then, the
database relations are composed, by the related
attributes and their functional dependencies, based on
the structures defined by Codd. Any random structural
composition of relations leads to INSERT, DELETE
and UPDATEanomalies
This paper presents a simple methodology that
blends the analytical approach and the synthetic
approach, to constitute the relations from a set of
attributes and minimally covered functional
dependencies, through the use of a dependency matrix
to get the desired manipulation. The distinct
attribute(s) from a set of functional dependencies is
identified for a separate relation. All thedependencies
are preserved and the lossless join is ensured by the
framed algorithm. Further, the Boyce-Codd Normal
Form (BCNF) is persuaded on each relation by
revamping the determinant attributes to candidatekey.

2. Related work
George C. Philip [8] proposes the practical role of
normalization in a database, addressing the confusion
created in the representation of attributes havingrepeating values, the removal of inconsistencies in the
definition of relations and the process of identification
of the candidate keys for normalized relations. W. Kent
[13] has framed the guidelines for the design of
normalized relations. These guidelines are more
general and understandable.
Fangjie Xu et al [7] have developed a Computer
Application Interface (CAI) tool. The tool designs thenormalized relations in a phased manner with all
attributes and functional dependencies. J. P. Nijsse et al
[9] have developed a step by step methodology to
develop a logical relational data model without the
required mathematical rigour. This methodology has
adopted the Synthetic approach. Tauqeer Hussain et al
[12] have proposed the elimination of the
normalization process itself fromdatabase design and
suggested instead the design of relations directly using
Entity-Relationship Diagrams and the functional
dependencies, which we presume, may enhance
complexity.
In this paper an attempt is made to design a BCNF
relation(s) with the preservation of all functional
dependencies and without losing any rigour of sound
“relational theory”.

Keywords: attribute, relation,BCNF, dependency
matrix, functional dependency

1. Introduction
In database schema design, the designer abstracts
the attributes and the functional dependencies among
the attributes from the SRS. The database schema is
designed from a number of relations, in which each
relation is structured by attributes and their functional
dependencies. Three layers of structuring a relation(s)
aredefined by the normalization process [3, 4, 5]. Any
random structural composition of relation(s) leads to
INSERT, DELETE and UPDATE anomalies, which
violate the good database design principles.
This paper proposes an automatic methodology that
uses various structures of the attributes and groups the

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3. Background
A functional dependency over a set...