外文翻译大学论文VIP专享

外文翻译大学论文西 南 交 通 大 学 本科毕业设计（英文翻译） 光电所图书借阅管理系统 年 级: 二〇〇七级 学 号: 20254165 姓 名: 王瑞华 专 业: 电子科学与技术 指导老师: 周伟 二〇一一年六月 西南交通大学本科毕业设计（英文翻译） 第 1 页 Database Management Systems A database (sometimes spelled data base) is also called an electronic database, referring to any collection of data, or information, that is specially organized for rapid search and retrieval by a computer. Databases are structured to facilitate the storage, retrieval , modification, and deletion of data in conjunction with various data-processing operations .Databases can be stored on magnetic disk or tape, optical disk, or some other secondary storage device. A database consists of a file or a set of files. The information in these files may be broken down into records, each of which consists of one or more fields. Fields are the basic units of data storage , and each field typically contains information pertaining to one aspect or attribute of the entity described by the database . Using keywords and various sorting commands, users can rapidly search , rearrange, group, and select the fields in many records to retrieve or create reports on particular aggregate of data. Complex data relationships and linkages may be found in all but the simplest databases .The system software package that handles the difficult tasks associated with creating ,accessing, and maintaining database records is called a database management system(DBMS).The programs in a DBMS package establish an interface between the database itself and the users of the database.. (These users may be applications programmers, managers and others with information needs, and various OS programs.) A...