计算机专业英语第四章.ppt

Introduction of Database Management Software Summarization of Database Lesson One Summarization of Database A database may be defined as a collection interrelated data stored together with as little redundancy as possible to serve one or more applications in an optimal fashion. be defined as interrelated redundancy optimal fashion Introduction to Relational Database Syntactically, the information that a field contains conforms to a certain type, such as a real, an integer, a character or a string. Semantically, the meaning of information within a field corresponds to the concept or attribute represented by the field. syntactically 语法上 field 字段 Integer 整型 Semantically 语义上 corresponds to 与…相对应 concept 概念 attribute 属性 represent 表示，象征 The relational database model followed on from hierarchical and network databases and is presently the most widely used data model for database. Prior to 1970, mainframe database applications were dominated by network and hierarchical models. relational database model 关系数据库模型 follow on 跟随，继承，在…之后 hierarchical 层次的 presently 目前，不久 widely 广泛地 prior to 在…之前，优先于 dominate 支配，统治 relationship 关系，关联 widespread 广泛的 acceptance 接受，容忍 straightforward 正直的，易懂的 conceptual 概念上的 algebra 代数 scheme 计划；阴谋，安排 be constructed from 由…构成 govern 统治，支配，管理 Data Base Management System (DBMS) The system software package that handles the difficult tasks associated with creating, accessing and maintaining data base records is called a database management system (DBMS). A DBMS will usually be handling multiple data calls concurrently. package n.包裹，包 handle n.柄, 手感；vt.触摸, 处理, 操作