Relational Database Concepts, Essay Example

The hierarchical concept

This is essentially a construct based upon a Parent Child relationship model.  For example in a retail store setting.  There may be a Furnishings Department.  This may be split into three subordinate areas i.e.  Home Furnishing,  Office Furnishings and Domestic Appliances.  These in turn may have additional lines of responsibility; hence you have a hierarchy of data being performed. The Department at the top, the subordinate areas in the middle and the detailed elements below.  Fig 1 refers.

Network concept

A network database is one where data elements are connected to one another through a series of links and best illustrated through an Entity Relationship (E-R) diagram.  In the example provided it shows the Entity, Attribute and the Relationship.  It describes whether the data has a 1: Many; 1:1; or Many to Many data relationships.  You are able to see through the model a complete representation of the networked data.

Relational database concept

A relational model has mainly three components:  (1)  A collection of objects or relations,. (2)   Operators that act on the objects or relations. (3) Data integrity methods.  A relational database management system (RDBMS) may be defined as : “all data is stored in Relations which (to the user) are tables with rows and columns. Each table is composed of records (called Tuples) and each record is identified by a field (attribute) containing a unique value. Every table shares at least one field with another table in ‘one to one,’ ‘one to many,’ or ‘many to many’ relationships.” (Business Dictionary, 2010).

The illustration to the right illustrates a typical Relational Database Design concept.  (Culbreth, 2010).

Three phases of traditional design method

In the design of Fernando’s database it is important to follow the three phases of traditional design: 1) Requirements Analysis  2) Data Modelling and 3) Normalization.

Requirements Analysis:  The Requirements analysis describes how the system should perform and entails a description of the system properties or attributes. In narrative terms this is a descriptive statement of the expectations of the system. The process covers the complex steps of documenting the requirements of the users, modeling and analysing these requirements and documenting these for system design. This is best accomplished in terms of an FSR report (Functional Specification of Requirements).

The Requirements Analysis will cover the following items:

• Definition of the system boundaries;
• Identification of the customer;
• Requirements Specification;
  • User Requirements
  • System Requirements
  • Data requirements

Data Modelling:  The data model is a graphic representation of the data that will be contained within the database storage. It is essentially a definition of the entities, attributes and relationships between data.  It forms an integral part of the requirements specification in the data requirements definition.   A graphical example of a data model is illustrated here.

Normalization :In data base design concepts normalization means the process of efficiently organizing data in a database.  This means the elimination of redundant data i.e. storing data twice in different tables, ensuring that the data dependencies make sense ( they relate to one another), getting the right nomenclatures i.e. apples, oranges and pears = fruit. “The database community has developed a series of guidelines for ensuring that databases are normalized. These are referred to as normal forms and are numbered from one (the lowest form of normalization, referred to as first normal form” (Chapple, 2010)

Works Cited

Business Dictionary. (2010). Relational Database. Retrieved 11 9, 2010, from Business Dictionary: http://www.businessdictionary.com/definition/relational-database.html

Chapple, M. (2010). Database Normalization basics. Retrieved 11 16, 2010, from About.com: http://databases.about.com/od/specificproducts/a/normalization.htm

Culbreth, M. (2010). Using Object Databases in .NET. Retrieved 11 9, 2010, from 15 Seconds: http://www.15seconds.com/issue/030407.htm