COMP3160 Discussion #1 Response

IAN FRANCIS 01602203 COMP3160 – DATABASE MANAGEMENT SYSTEMS DISCUSSION SET# 1

COMP3160 1. Describe Describe the basic basic features features of the relational relational data model, model, and discuss discuss their  their  importance to the end user and the designer.

The basic features of the Relational Data Model are its program data independence , this relates to the ability of changes to be made to the database such as addition of attributes or method of accessing records without necessitating modification and recompilation of all programs that access the database. Structural data independence is also a basic feature of the Relational Data Model. This means you can query the database without navigating the structure of the database which would be necessary in the tree like structure of its  predecessor the Hierarchical model. The basic structure of the model is the table which is conceptually simple making it easy to use by end users and designers while the Hierarchical Data model is not as flexible and is best for queries that are structured and known at design time.

3. Briefly explain three three (often conflicting) conflicting) database requirements that must be addressed in database design? “Designers must make design compromises that are triggered by conflicting goals such as adherence to design standards (design elegance) , processing speed and information requirements.” Design standards help us to develop structures that minimize data redundancies, thereby minimizing the likelihood of data inconsistencies. High processing speeds are given top priority in some organization. High  processing speed also requires the minimization of access time which is usually achieved by minimizing the number and complexity of logically desirable relationships, which can lead to conflict with design standards.

Timely information might be the focus of data design in other organizations. Complex information requirement s may dictate data transformations, and they may expand the number of entities and attributes. (resulting in reduced transaction speeds) Hence to ensure maximum information generation , we sometime have to sacrifice high processing speeds.

2. Discuss the difference between transaction database and data warehouse databases.

A Transactional database is intended for day to day transaction which places emphasis on timely and accurate recording of those transactions while Data warehouse database’ emphasis is on generating complex queries to assist the organization with its strategic planning decisions. The type of queries carried out on a transactional database are more structured whereas the queries carried out on Data warehousing databases are complex and not structured at all.