数据库系统 Database Systems-外文资料原文.doc

外文资料原文 Database Systems Introduction to Database System Today, more than at any previous time, the success of an organization depends on its ability to acquire accurate and timely data about its operation, to manage this data effectively, and to use it to analyze and guide its activities. Phrases such as the information superhighway have become ubiquitous, and information processing is a rapidly growing multibillion dollar industry . The amount of information available to us is literally exploding, and the value of data as an organizational asset is being widely recognized. This paradox drives the need for increasingly powerful and flexible data management systems . A database is a collection of data , typically describing the activities of one or more related organizations . For example , a university database might contain information about the following . ●Entities such as students , faculty , courses , and classrooms . ●Relationships between entities , such as students’ enrollment in courses , faculty teaching courses , and the use of rooms for courses . A database management system , or DBMS , is software designed to assist in maintaining and utilizing large collections of data , and the need for such systems , as well as their use , is growing rapidly . The alternative to using a DBMS is to use ad hoc approaches that do not carry over from one application to another , for example , to store the data in files and write application-specific code to manage it . The area of database management systems is a microcosm of computer science in general . The issues addressed and the techniques used span a wide spectrum , including languages , object-orientation and other programming paradigms , compilation , operating systems concurrent programming , data structures , algorithms ,theory , parallel and distributed systems , user interfaces , expert systems and artificial intelligence , statistical techniques , and dynamic programming . Database management continu