“Everything has changed, except our way of thinking.” - Albert Einstein Data are a vital organizational resource that needs to be managed like other important business assets. Today’s business enterprises cannot survive or succeed without quality data about their internal operations and external environment. This growth drives corporations to analyze every bit of information that is extracted from huge data warehouses for competitive advantage. This has turned the data storage and management function into a key strategic role of information age. I.Background
1. Evolution of Data Systems
The demand for information has rise in every organization. Organizations have steadily become global and widespread. Organizations have to contend with fierce competitive pressures. They need vast and complex information to stay in business and make a profit. For the past three decades, people have witnessed a huge, explosive growth in information technology. Processors have become faster, cheaper, and smaller. Operating systems have become powerful and robust. Data storage media have expanded tremendously in capacity; data storage prices have tumbled. Network and communication technology can now connect any remote site without difficulty. Application programming and people-machine interface have dramatically improved.
Figure.1 Technology growth and demand for information
The escalating demand for information and the explosive growth in information technology have worked hand in hand to bring about the evolution to database systems. Ever-increasing demand for information drives the need for better methods of storing and retrieving data, for faster ways of processing data, and for improved methods of providing information. From manual-type records to sequential files and currently to databases, the demand for more and better information drove the technology growth. Progress in technology, in turn, spurred the capability to provide different types of information, not just to run day-to-day operations of an organization, but also to make strategic decisions.
II.Database and Data Warehouses
1.The Database Approach
A.Database: A Formal Definition
Database is a collection of records stored in a computer in a systematic way that provides data for many applications. For better retrieval and sorting, each record is usually organized as a set of data elements (facts). The items retrieved in answer to queries become information that can be used to make decisions. The computer program used to manage and query a database is known as a database management system (DBMS). B.Types of Database
Operational databases store detailed data in support of the business process and operations of a company. Examples include customer database, inventory database, and other databases containing data generated by business operations. ii.Distributed Databases
Distributed databases are databases that are distributed to network servers or on other company networks. Replication and distribution of databases are done to improve database performance at end-user work sites. iii.External Databases
External databases include hypermedia databases consisting of hyperlinked pages of multimedia (texts, graphics, images, videos). C.Driving Forces of Adopting Database Systems
i.Information as a Corporate Asset
Today, executives of the companies understand that it is essential to manage information as a corporate key asset. They understand the need of using database to improved methods for storing, retrieving, and using information. 2.Explosive Growth of Computer Technology
Computer technology, especially data storage and retrieval systems, has grown in a phenomenal manner. It has progressed to database systems that need sophisticated ways of data storage and retrieval. 3.Escalating Demand for Information
The increase in demand for information by organizations, not only in volume but in...