A DBMS can organize， process， and present selected data elements from the database. This capability enables decision makers to search， probe， and query database contents in order to extract answers to nonrecurring and unplanned questions that aren't available in regular reports. These questions might initially be vague and/or poorly defined， but people can "browse" through the database until they have the needed information. In short， the DBMS will "manage" the stored data items and assemble the needed items from the common database in response to the queries of those who aren't programmers. In a file-oriented system， users needing special information may communicate their needs to a programmer， who， when time permits， will write one or more programs to extract the data and prepare the information. The availability of a DBMS， however， offers users a much faster alternative communications path.
The management information system （MIS） concept has been defined in dozens of ways. Since one organization's model of an MIS is likely to differ from that of another， it's not surprising that their MIS definitions would also vary in scope and breadth. For our purposes， an MIS can be defined as a network of computer based data processing procedures developed in an organization and integrated as necessary with manual and other procedures for the purpose of providing timely and effective information to support decision-making and other necessary management functions.
【Vocabulary】
logically
adv. 伦理上地，逻辑上地
scroll
n. 卷轴，名册 v. 成卷形
handle
n. 柄，把手 vt. 处理，操作
access
vt. 存取，接近 n. 通路，入门
retrieval
n. 取回，恢复，挽救
linkage
n. 连接
probe
vt. 探查，查明 n. 探针，探测器
query
n. 质问，询问，怀疑
nonrecurring
adj. 不重现的
vague
adj. 含糊的，茫然的
definition
n. 定义，解说，精确度
scope
n. 范围，机会，余地
breadth
n. 宽度，幅宽
based
v. 基于，以…为基础
【参考译文】
数据库管理系统和管理信息系统
众所周知，数据库是汇集逻辑上相关数据元的集合。这些数据元可以按照不同的结构组织起来，以满足单位和个人的多种处理和检索功能的需要。数据库本身并不是什么新鲜的事物——早期的数据刻在石头上，记在名册上，或是写在索引卡中。然而现在数据库普遍记录在可磁化的介质上，并且需要用计算机程序来执行必需的存储和检索操作。
如下所述，所有数据库中（最简单的除外）都有复杂的数据关系及其链接。处理、创建、访问及维护数据库来记录有关的复杂任务的系统软件包叫做数据库管理系统（DBMS）。DBMS软件包中的程序在数据库与它的用户之间建立接口。（这些用户包括应用程序员、管理员，以及其他需要信息的人员和各种操作系统程序。）
DBMS可以组织、处理和表示从数据库中选出的数据元。这种功能使决策者能够搜索、探查和查询数据库的内容，从而对在正规报告中没有的、不再出现的而且无法预料的问题做出回答。这些问题最初可能是模糊的或者定义是不确切的，但是人们可以浏览数据库直到获得所需要的信息。简单地说，就是DBMS将“管理”存储的数据，并且从公共数据库中汇集所需要的数据以回答非程序员的提问。在面向文件的系统中，需要特定信息的用户应该将他们的要求传送给程序员。该程序员在时间的允许下，将会编写一个或多个程序来提取数据和准备信息。然而DBMS的可用性为用户提供了一个更加快速的替代通信通道。
管理信息系统（MIS）已经用多达数十次的概念定义过。因为MIS的组织模型可能各不相同，所以 MIS 的定义随应用范围的扩大而变化就不值得奇怪了。本文以为，MIS系统可以定义为基于计算机的数据处理过程的网络系统，它是一个为了支持决策和其他必需的管理功能提供及时有效的信息而开发的机构，并且可以按照需要把人工和其他过程结合在一起。
【Reading Material】
Decision Support Introduction
Database management systems are widely used by organizations for maintaining data that documents their everyday operations. In applications that update such operational data， transactions typically make small changes （for example， adding a reservation or depositing a check） and a large number of transactions must be reliably and efficiently processed， Such On-Line Transaction Processing（OLTP）， applications have driven the growth of the DBMS industry in the past three decades， and will doubtless continue to be important. DBMS have traditionally been optimized extensively to perform well in such applications.
Recently， however， organizations have increasingly emphasized applications in which current and historical data are comprehensively analyzed and explored， identifying useful trends and creating summaries of the data， in order to support high-level decision making. Such applications are referred to as decision support. Decision support has rapidly grown into a multibillion-dollar industry， and further growth is expected. There are a number of vendors offering database systems and tools to facilitate decision support. Industry organizations are emerging to set standards and create consensus on issues like language and architecture design. In this chapter our goal is to provide an introduction to the major new issues， and to place decision support systems in the broader context of database management systems.
Organizational decision making requires a comprehensive view of all aspects of an enterprise， and many organizations have therefore created consolidated data warehouses that contain data drawn from several databases maintained by different business units， together with historical and summary information.
The trend towards data warehousing is complemented by an increased emphasis on powerful analysis tools. Three broad classes of analysis tools are emerging. First， there ate DBMS that support traditional SQL-style queries， but designed to support complex queries efficiently. Such systems can be regarded as relational DBMS6 optimized for decision support applications.
Second， there are systems that support a class of stylized queries that typically involve group-by and aggregation operators. Applications dominated by such queries are called On-Line Analytic Processing， or OLAP. These systems support a querying style in which the data is best thought of as a multidimensional array， and are influenced by end-user tools such as spreadsheets， in addition to database query languages.
