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1、英文原文及中文翻译DATABASE一、DATABASE MANAGEMENT SYSTEMS (DBMS) ANDMANAGEMENT INFORMATION SYSTEM (MIS)You know that a database is a collection of logically related data elements that may be structured in various ways to meet the multiple processing and retrieval needs of organizations and individuals. Theres
2、nothing new about databases-early ones were chiseled in stone, penned on scrolls, and written on index cards. But now databases are commonly recorded on magnetically media, and computer programs are required to perform the necessary storage and retrieval operations.Youll see in the following pages t
3、hat 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
4、 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 DBMS can organize, process, and present selected data elements from the database. This capability e
5、nables decision makers to search, probe, and query database contents in order to extract answers to nonrecurring and unplanned questions that arent available in regular reports. These questions might initially be vague and/or poorly defined, but people can browse through the database until they have
6、 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 arent programmers. In a file-oriented system, users needing special information may communicate their needs to a programmer, wh
7、o, when time permits, will write one or more programs to extract the data and prepare the informationc4. The availability of a DBMS, however, offers users a much faster alternative communications path (see Fig. 7-1).The management information system (MIS) concept has been defined in dozens of ways.
8、Since one organizations model of an MIS is likely to differ from that of another, its 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 int
9、egrated 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.Although MIS models differ, most of them recognize the concepts shown in Fig. 7-2. In addition to what might be term
10、ed the horizontal management structure shown in Fig. 7-2(a), an organization is also divided vertically into different specialities and functions which require separate information flows (see Fig. 7-2 (b). Combining the horizontal managerial levels with the vertical specialities produces the complex
11、 organizational structure shown in Fig. 7-2(e). Underlying this structure is a database consisting, ideally, of internally and externally produced data relating to past, present, and predicted furture events.The formidable task of the MIS designer is to develop the information flow needed to support
12、 decision making (see Fig. 7-3) Generally speaking, much of the information needed by managers who occupy different levels and who have different responsibilities is obtained from a collection of existing information systems (or subsystems) . These systems may be tied together very closely in an MIS
13、. More often, however, they are more loosely coupled.二、SQL AND SQL SERVERIBM invented a computer language back in the 1970s designed specifically for database queries called SEQUEI.; those letters stand for Structured English Query Language. Over time, the language has been added to so that it is no
14、t just a language for queries, but can also build databases and manage the database engines security. IBM released SEQUEl. into the public domain, where it became known as SQL. Because of this heritage you can pronounce it sequel or spell it out S-Q-I. There are various versions of SQL used in today
15、s database engines. Microsoft SQL Server uses a version called Transact-SQL, or T-SQL, which stands for Transaction SQL.1. What Is SQL Server?SQL Server is a client/server relational database management system (RDBMS) that uses Transact-SQl. to send requests between a client and SQl. Server.2. Clien
16、t/Server ArchitectureThe terms client, server, and client/server can be used to refer to very general concepts or to specific items of hardware or software. At the most general level, a client is any component of a system that requests services or resources from other components of a system. A server is any component of a system that provides services or resources t
