当前位置:文档之家› 数据库管理系统介绍 外文翻译

数据库管理系统介绍 外文翻译

数据库管理系统介绍 外文翻译
数据库管理系统介绍 外文翻译

外文资料

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 DBMS can organize, process, and present selected data elements form 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.

A database management system (DBMS) is composed of three major parts:(1)a storage subsystem that stores and retrieves data in files;(2) a modeling and manipulation subsystem that provides the means with which to organize the data and to add , delete, maintain, and update the data;(3)and an interface between the DBMS and its users. Several major trends are emerging that enhance the value and usefulness of database management systems;

Managers: who require more up-to-data information to make effective decision

Customers: who demand increasingly sophisticated information services and more current information about the status of their orders, invoices, and accounts.

Users: who find that they can develop custom applications with database systems in a fraction of the time it takes to use traditional programming languages.

Organizations : that discover information has a strategic value; they utilize their database systems to gain an edge over their competitors. The Database Model

A data model describes a way to structure and manipulate the data in a database. The structural part of the model specifies how data should be represented(such as tree, tables, and so on ).The manipulative part of the model specifies the operation with which to add, delete, display, maintain, print, search, select, sort and update the data.

Hierarchical Model

The first database management systems used a hierarchical model-that is-they arranged records into a tree structure. Some records are root records and all others have unique parent records. The structure of the tree is designed to reflect the order in which the data will be used that is ,the record at the root of a tree will be accessed first, then records one level below the root ,and so on.

The hierarchical model was developed because hierarchical relationships are commonly found in business applications. As you have known, an organization char often describes a hierarchical relationship: top management is at the highest level, middle management at lower levels, and operational employees at the lowest levels. Note that within a strict hierarchy, each level of management may have many employees or levels of employees beneath it, but each employee has only one manager. Hierarchical data are characterized by this one-to-many relationship among data.

In the hierarchical approach, each relationship must be explicitly defined when the database is created. Each record in a hierarchical database can contain only one key field and only one relationship is allowed

between any two fields. This can create a problem because data do not always conform to such a strict hierarchy.

Relational Model

A major breakthrough in database research occurred in 1970 when E. F. Codd proposed a fundamentally different approach to database management called relational model ,which uses a table as its data structure.

The relational database is the most widely used database structure. Data is organized into related tables. Each table is made up of rows called and columns called fields. Each record contains fields of data about some specific item. For example, in a table containing information on employees, a record would contain fields of data such as a person’s last name ,first name ,and street address.

Structured query language(SQL)is a query language for manipulating data in a relational database .It is nonprocedural or declarative, in which the user need only specify an English-like description that specifies the operation and the described record or combination of records. A query optimizer translates the description into a procedure to perform the database manipulation.

Network Model

The network model creates relationships among data through a linked-list structure in which subordinate records can be linked to more than one parent record. This approach combines records with links, which are called pointers. The pointers are addresses that indicate the location of a record. With the network approach, a subordinate record can be linked to a key record and at the same time itself be a key record linked to other

sets of subordinate records. The network mode historically has had a performance advantage over other database models. Today , such performance characteristics are only important in high-volume ,high-speed transaction processing such as automatic teller machine networks or airline reservation system.

Both hierarchical and network databases are application specific. If a new application is developed ,maintaining the consistency of databases in different applications can be very difficult. For example, suppose a new pension application is developed .The data are the same, but a new database must be created.

Object Model

The newest approach to database management uses an object model , in which records are represented by entities called objects that can both store data and provide methods or procedures to perform specific tasks.

The query language used for the object model is the same object-oriented programming language used to develop the database application .This can create problems because there is no simple , uniform query language such as SQL . The object model is relatively new, and only a few examples of object-oriented database exist. It has attracted attention because developers who choose an object-oriented programming language want a database based on an object-oriented model.

Distributed Database

Similarly , a distributed database is one in which different parts of the database reside on physically separated computers . One goal of distributed databases is the access of information without regard to where the data might be stored. Keeping in mind that once the users and their data are

separated , the communication and networking concepts come into play .

Distributed databases require software that resides partially in the larger computer. This software bridges the gap between personal and large computers and resolves the problems of incompatible data formats. Ideally, it would make the mainframe databases appear to be large libraries of information, with most of the processing accomplished on the personal computer.

A drawback to some distributed systems is that they are often based on what is called a mainframe-entire model , in which the larger host computer is seen as the master and the terminal or personal computer is seen as a slave. There are some advantages to this approach . With databases under centralized control , many of the problems of data integrity that we mentioned earlier are solved . But today’s personal computers, departmental computers, and distributed processing require computers and their applications to communicate with each other on a more equal or peer-to-peer basis. In a database, the client/server model provides the framework for distributing databases.

One way to take advantage of many connected computers running database applications is to distribute the application into cooperating parts that are independent of one anther. A client is an end user or computer program that requests resources across a network. A server is a computer running software that fulfills those requests across a network . When the resources are data in a database ,the client/server model provides the framework for distributing database.

A file serve is software that provides access to files across a network.

A dedicated file server is a single computer dedicated to being a file server.

This is useful ,for example ,if the files are large and require fast access .In such cases, a minicomputer or mainframe would be used as a file server. A distributed file server spreads the files around on individual computers instead of placing them on one dedicated computer.

Advantages of the latter server include the ability to store and retrieve files on other computers and the elimination of duplicate files on each computer. A major disadvantage , however, is that individual read/write requests are being moved across the network and problems can arise when updating files. Suppose a user requests a record from a file and changes it while another user requests the same record and changes it too. The solution to this problems called record locking, which means that the first request makes others requests wait until the first request is satisfied . Other users may be able to read the record, but they will not be able to change it .

A database server is software that services requests to a database across a network. For example, suppose a user types in a query for data on his or her personal computer . If the application is designed with the client/server model in mind ,the query language part on the personal computer simple sends the query across the network to the database server and requests to be notified when the data are found.

Examples of distributed database systems can be found in the engineering world. Sun’s Network Filing System(NFS),for example, is used in computer-aided engineering applications to distribute data among the hard disks in a network of Sun workstation.

Distributing databases is an evolutionary step because it is logical that data should exist at the location where they are being used .

Departmental computers within a large corporation ,for example, should have data reside locally , yet those data should be accessible by authorized corporate management when they want to consolidate departmental data . DBMS software will protect the security and integrity of the database , and the distributed database will appear to its users as no different from the non-distributed database .

In this information age, the data server has become the heart of a company. This one piece of software controls the rhythm of most organizations and is used to pump information lifeblood through the arteries of the network. Because of the critical nature of this application, the data server is also the one of the most popular targets for hackers. If a hacker owns this application, he can cause the company's "heart" to suffer a fatal arrest.

Ironically, although most users are now aware of hackers, they still do not realize how susceptible their database servers are to hack attacks. Thus, this article presents a description of the primary methods of attacking database servers (also known as SQL servers) and shows you how to protect yourself from these attacks.

You should note this information is not new. Many technical white papers go into great detail about how to perform SQL attacks, and numerous vulnerabilities have been posted to security lists that describe exactly how certain database applications can be exploited. This article was written for the curious non-SQL experts who do not care to know the details, and as a review to those who do use SQL regularly.

What Is a SQL Server?

A database application is a program that provides clients with access

to data. There are many variations of this type of application, ranging from the expensive enterprise-level Microsoft SQL Server to the free and open source mySQL. Regardless of the flavor, most database server applications have several things in common.

First, database applications use the same general programming language known as SQL, or Structured Query Language. This language, also known as a fourth-level language due to its simplistic syntax, is at the core of how a client communicates its requests to the server. Using SQL in its simplest form, a programmer can select, add, update, and delete information in a database. However, SQL can also be used to create and design entire databases, perform various functions on the returned information, and even execute other programs.

To illustrate how SQL can be used, the following is an example of a simple standard SQL query and a more powerful SQL query:

Simple: "Select * from dbFurniture.tblChair"

This returns all information in the table tblChair from the database dbFurniture.

Complex: "EXEC master..xp_cmdshell 'dir c:\'"

This short SQL command returns to the client the list of files and folders under the c:\ directory of the SQL server. Note that this example uses an extended stored procedure that is exclusive to MS SQL Server.

The second function that database server applications share is that they all require some form of authenticated connection between client and host. Although the SQL language is fairly easy to use, at least in its basic form, any client that wants to perform queries must first provide some form of credentials that will authorize the client; the client also must

define the format of the request and response.

This connection is defined by several attributes, depending on the relative location of the client and what operating systems are in use. We could spend a whole article discussing various technologies such as DSN connections, DSN-less connections, RDO, ADO, and more, but these subjects are outside the scope of this article. If you want to learn more about them, a little Google'ing will provide you with more than enough information. However, the following is a list of the more common items included in a connection request.

Database source

Request type

Database

User ID

Password

Before any connection can be made, the client must define what type of database server it is connecting to. This is handled by a software component that provides the client with the instructions needed to create the request in the correct format. In addition to the type of database, the request type can be used to further define how the client's request will be handled by the server. Next comes the database name and finally the authentication information.

All the connection information is important, but by far the weakest link is the authentication information—or lack thereof. In a properly managed server, each database has its own users with specifically designated permissions that control what type of activity they can perform. For example, a user account would be set up as read only for applications

that need to only access information. Another account should be used for inserts or updates, and maybe even a third account would be used for deletes. This type of account control ensures that any compromised account is limited in functionality. Unfortunately, many database programs are set up with null or easy passwords, which leads to successful hack attacks.

译文

数据库管理系统介绍

数据库也可以称为电子数据库,是专门组织起来的一组数据或信息,其目的是为了便于计算机快速查询及检索。数据库的结构是专门设计的,在各种数据处理操作命令的支持下,可以简化数据的存储,检索,修改和删除。数据库可以存储在磁盘,磁带,光盘或其他辅助存储设备上。

数据库由一个或一套文件组成,其中的信息可以分解为记录,每一记录又包含一个或多个字段(或称为域)。字段是数据存取的基本单位。数据库用于描述实体,其中的一个字段通常表示与实体的某一属性相关的信息。通过关键字以及各种分类(排序)命令,用户可以对多条记录的字段进行查询,重新整理,分组或选择,以实体对某一类数据的检索,也可以生成报表。

所有数据库(最简单的除外)中都有复杂的数据关系及其链接。处理与创建,访问以及维护数据库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其用户间建立接口。(这些用户可以是应用程序员,管理员及其他需要信息的人员和各种操作系统程序)。

DBMS可组织,处理和表示从数据库中选出的数据元。该功能使决策者能搜索,探查和查询数据库的内容,从而对在正规报告中没有的,不再出现的且无法预料的问题做出回答。这些问题最初可能是模糊的并且(或者)是定义不恰当的,但是人们可以浏览数据库直到获得所需的信息。简言之,DBMS将“管理”存储的数据项,并从公共数据库中汇集所需的数据项以回答非程序员的询问。

DBMS由3个主要部分组成:(1)存储子系统,用来存储和检索文件中的数据;(2)建模和操作子系统,提供组织数据以及添加,删除,维护,更新数据的方法;(3)用户和DBMS之间的接口。在提高数据库管理系统的价值和有效性方面正在展现以下一些重要发展趋势;

1.管理人员需要最新的信息以做出有效的决策。

2.客户需要越来越复杂的信息服务以及更多的有关其订单,发票和账号的当前信息。

3.用户发现他们可以使用传统的程序设计语言,在很短的一段时间内用数据库系统开发客户应用程序。

4.商业公司发现了信息的战略价值,他们利用数据库系统领先于竞争对手。

数据库模型

数据库模型描述了在数据库中结构化和操纵数据的方法,模型的结构部分规定了数据如何被描述(例如树,表等):模型的操纵部分规定了数据添加,删除,显示,维护,打印,查找,选择,排序和更新等操作。

分层模型

第一个数据库管理系统使用的是分层模型,也就是说,将数据记录排列成树形结构。一些记录时根目录,在其他所有记录都有独立的父记录。树形结构的设计反映了数据被使用的顺序,也就是首先访问处于树根位置的记录,接下来是跟下面的记录,等等。

分层模型的开发是因为分层关系在商业应用中普遍存在,众所周知,一个组织结构图表就描述了一种分层关系:高层管理人员在最高层,中层管理人员在较低的层次,负责具体事务的雇员在最底层。值得注意的是,在一个严格的分层结构体系中,在每个管理层下可能有多个雇员或多个层次的雇员,但每个雇员只有一个管理者。分层结构数据的典型特征是数据之间的一对多关系。

在分层方法中,当数据库建立时,每一关系即被明确地定义。在分层数据库中的每一记录只能包含一个关键字段,任意两个字段之间只能有一种关系。由于数据并不总是遵循这种严格的分层关系,所以这样可能会出现一些问题。

关系模型

在1970年,数据库研究取得了重大突破。E.F.Codd提出了一种截然不同的数据库管理方法,使用表作为数据结构,称之为关系模型.

关系数据库是使用最广的数据结构,数据被组织成关系表,每个表由称作记录的行和称作字段的列组成。每个记录包含了专用项目的字段值。例如,在一个包含雇员信息的表中,一个记录包含了像一个人姓名和地址这样的字段的值。

结构化查询语言(SQL)是一种在关系型数据库中用于处理数据的查询语言。它是非过程化

语言或者说是描述性的,用户只须指定一种类似于英语的描述,用来确定操作,记录或描述记录组合。查询优化器将这种描述翻译为过程执行数据库操作。

网状模型

网状模型在数据之间通过链接表结构创建关系,子记录可以链接到多个父记录。这种将记录和链接捆绑到一起的方法叫做指针,他是指向一个记录存储位置的存储地址。使用网状方法,一个子记录可以链接到一个关键记录,同时,它本身也可以作为一个关键记录。链接到其他一系列子记录。在早期,网状模型比其他模型更有性能优势;但是在今天,这种优势的特点只有在自动柜员机网络,航空预定系统等大容量和高速处理过程中才是最重要的。

分层和网状数据库都是专用程序,如果开发一个新的应用程序,那么在不同的应用程序中保持数据库的一致性是非常困难的。例如开发一个退休金程序,需要访问雇员数据,这一数据同时也被工资单程序访问。虽然数据是相同的,但是也必须建立新的数据库。

对象模型

最新的数据库管理方法是使用对象模型,记录由被称作对象的实体来描述,可以在对象中存储数据,同时提供方法或程序执行特定的任务。

对象模型使用的查询语言与开发数据库程序所使用的面向对象的程序设计语言是相同的,因为没有像SQL这样简单统一的查询语言,所以会产生一些问题。对象模型相对较新,仅有少数几个面向对象的数据库实例。它引起了人们的关注,因为选择面向对象程序设计语言的开发人员希望有一个基于在对象模型基础上的数据库。

分布式数据库

类似的,分布式数据库指的是数据库的各个部分分别存储在物理上相互分开的计算机上。分布式数据库的一个目的是访问数据信息时不必考虑其他位置。注意,一旦用户和数据分开,通信和网络则开始扮演重要角色。

分布式数据库需要部分常驻于大型主机上的软件,这些软件在大型机和个人计算机之间建立桥梁,并解决数据格式不兼容的问题。在理想情况下,大型主机上的数据库看起来像是一个大的信息仓库,而大部分处理则在个人计算机上完成。

分布式数据库系统的一个缺点是它们常以主机中心模型为基础,在这种模型中,大型主机

看起来好像是雇主,而终端和个人计算机看起来好像是奴隶。但是这种方法也有许多优点:由于数据库的集中控制,前面提到的数据完整性和安全性的问题就迎刃而解了。当今的个人计算机,部门级计算机和分布式处理都需要计算机之间以及应用程序之间在相等或对等的基础上相互通信,在数据库中客户机/服务器模型为分布式数据库提供了框架结构。

利用相互连接的计算机上运行的数据库应用程序的一种方法是将程序分解为相互独立的部分。客户端是一个最终用户或通过网络申请资源的计算机程序,服务器是一个运行着的计算机软件,存储着那些通过网络传输的申请。当申请的资源是数据库中的数据时,客户机/服务器模型则为分布式数据库提供了框架结构。

文件服务器指的是一个通过网络提供文件访问的软件,专门的文件服务器是一台被指定为文件服务器的计算机。这是非常有用的,例如,如果文件比较大而且需要快速访问,在这种情况下,一台微型计算机或大型主机将被用作文件服务器。分布式文件服务器将文件分散到不同的计算机上,而不是将它们集中存放到专门的文件服务器上。

后一种文件服务器的优点包括在其他计算机上存储和检索文件的能力,并可以在每一台计算机上消除重复文件。然而,一个重要的缺点是每个读写请求需要在网络上传播,在刷新文件时可能出现问题。假设一个用户申请文件中的一个数据并修改它,同时另外一个用户也申请这个数据并修改它,解决这种问题的方法叫做数据锁定,即第一个申请使其他申请处于等待状态,直到完成第一个申请,其他用户可以读取这个数据,但不能修改。

数据库服务器是一个通过网络为数据库申请提供服务的软件,例如,假设某个用户在他的个人计算机上输入了一个数据查询命令,如果应用程序按照客户机/服务器模型设计,那么这个人计算机上的查询语言通过网络传送数据库服务器上,当发现数据时发出通知。

在工程界也有许多分布式数据库的例子,如SUN公司的网络文件系统(NFS)被应用到计算机辅助工程应用程序中,将数据分散到由SUN工作站组成的网络上的不同硬盘之间。

分布式数据库是革命性的进步,因为把数据存放在被使用位置上是很合乎常理的。例如一个大公司不同部门之间的计算机,应该将数据存储在本地,然而,当被授权的管理人员需要整理部门数据时,数据应该能够被访问。数据库信息系统软件将保护数据库的安全性和完整性,对用户而言,分布式数据库和非分布式数据库看起来没有什么差别。

在这个信息时代,数据管理服务器已经成为公司的核心。这一个软件的模块控制整个组织的顺利运行就如同人身体动脉使得鲜血在身体中流通顺畅。因为这个所以就要把好身份申请这一关,数据管理服务器也是黑客最为关心的目标之一。如果一旦自己的身份验证被黑客攻克,他将能引起公司的"心脏" 遭受致命的破坏。

虽然大多数的使用者现在知道黑客,但是他们仍然不了解他们的数据库伺候器是多么的易受影响黑客的攻击。因此,这篇文章介绍是如何攻击数据库伺候器(比如SQL 伺候器) 和讲述你在受攻击时该如何保护你自己的数据。

我们应该注意信息不断更新。许多技术上的空白导致了SQL 在运行时很多细节被攻击的事,而且很多的易受攻击的地方被寄到完全地描述数据库申请能是多么的某开发的安全目录。这个文章对那些好奇的非SQL 专家是书面的不关心知道细节,而且如检讨到那些做的人有规则地使用SQL。

一个SQL 伺候器是做什么的?

一个数据库身份验证是一个提供给有权限客户访问数据通道。申请的类型有许多变化,从大企业的微软SQL 伺候器到自由的和开放来源mySQL 排列。不管是什么,大多数的数据库伺候器申请都有共同的一些功能。

首先,数据库申请使用都使用相同的SQL 的语言,或结构查询语言。这些语言,也属于第四代语言,由于它单纯化的语法,是在一位客户如何向伺候器传达它的请求核心。使用它最简单的形式语言SQL ,一个程序师能选择,增加,更新,而且在一个数据库中能划分各种数据。然而,SQL 也能用来产生并且设计整个的数据库,运行被送回的数据上的各种不同的功能,甚至运行其他的程序。

为了要举例说明SQL 如何使用,下列各项是简单标准SQL 的一个例子疑问和一个比较复杂的SQL 疑问:

简单的:"挑选出来的*从dbFurniture.tblChair"

这在来自数据库dbFurniture 的数据库tblChair 中返还的所有数据.

复杂:"管理人员征服。xp_cmdshell'dir c 。:\'"

这个短SQL 指令回到客户文件和文件夹的目录在SQL 伺候器的c:\directory 之下,

注意这个例子使用一个广大的储存对MS SQL 伺候器是独家的程序。

第二个功能数据库伺候器申请部份是他们全部需要一些形式的验证进行建立客户和主机之间的连接。虽然SQL 语言基本语法形式使用中很容易。他只要建立一些基础的形式就行了,想要运行任何客户的疑问一定要首先提供一些形式,这将会授权与客户的国书;客户也要有一定的定义请求和回应的格式。

这个连接被一些属性定义,仰赖客户的相关位置和什么操作系统是在使用中,我们可以花费整个文章讨论例如DSN 连接,较少的DSN-连接,RDO ,费力和更多的各种不同的技术,但是这些主题超过了这个文章的范围。如果你想要学习更多有关他们,一些Google'ing 将会提供更充足的数据给你。然而,下列各项是被包含在关系中一些连接请求的一连串的比较通常的项目。

数据库来源

请求类型

数据库

使用者身份证

密码

任何的连接在连接之前,客户要连接到什么类型的伺候器。这被一个提供被需要在正确的格式中产生请求的指令给客户的软件成份处理。除了数据库的类型,请求类型能用来比较进一步定义客户的请求将会如何被伺候器处理。下一个来数据库名字和最后证明数据。

所有的连接信息都很重要,但是显然最弱的联编是关于证明数据或缺乏。在适当地处理了伺候器。每个数据库明确地用有它的自己使用者指定了控制他们能运行什麽类型的活动许可。举例来说,一个使用者帐户会是建立如申请所只有读哪一对唯一的通路数据需要。另外的一个帐户应该作为插入物或更新,而且也许甚至一个第三帐户会是使用过的因为划除。帐户控制的这个类型确定那个任何的被妥协处理的帐户在功能性中被限制。不幸地,许多数据库计画是建立由于无效力的或容易的密码,导致成功的攻击。

Modern Database Management

7 th Edition Jeffrey A. Hoffer, Mary B.

Prescott,

Fred R. McFadden

外文翻译-数据库管理系统—剖析

Database Management System Source:Database and Network Journal Author:David Anderson You know that a data is a collection of logically related data elements that may be structured in various ways to meet the multiple processing and retrieval needs of orga nizations and individuals. There’s nothing new about data base-early ones were chiseled in stone, penned on scrolls, and written on index cards. But now database are commonly recorded on magnetically media, and computer programs are required to perform the necessary storage and retrieval operations. The system software package that handles the difficult tasks associated with created, accessing, and maintaining database records is 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 programmers.) A DBMS can organize, process, and present selected data elements from the database. This capability enables decision makers to search. Probe, and query data 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 programmers, who, when time permits, will information. The availability of a DBMS, however, offers users a much faster alternative communications patch (see figure). Special, direct, and other file processing approaches ate used to organize and structure data in single files. But a DBMS is able to integrate data elements from several files to answer specific user inquiries fir information. This means that the DBMS is able to structure and tie together the logically related data from several large files. Logical structures. Identifying these logical relationships is a job of the data administrator. A data definition language is used for this purpose. The DBMS may

管理信息系统外文翻译

管理信息系统外文翻译-标准化文件发布号:(9456-EUATWK-MWUB-WUNN-INNUL-DDQTY-KII

英文文献翻译 二〇年月日

科技文章摘译 Definition of a Management Information System There is no consensus of the definition of the term "management information system". Some writers prefer alternative terminology such as "information processing system", "information and decision system", "organizational information system", or simply "information system" to refer to the computer-based information processing system which supports the operations, management, and decision-making functions of an organization. This text uses “MIS” because it is descriptive and generally understood; it also frequently uses “information system” instead of “MIS” to refer to an organizational information system. A definition of a management information system, as the term is generally understood, is an integrated, user-machine system for providing information to support operations, management, and decision-making functions in an organization. The system utilizes computer hardware and software; manual procedures; models for analysis planning, control and decision making; and a database. The fact that it is an integrated system does not mean that it is a single, monolithic structure; rather, it means that the parts fit into an overall design. The elements of the definition are highlighted below. 1 Computer-based user-machine system Conceptually, management information can exist without computer, but it is the power of the computer which makes MIS feasible. The question is not whether computers should be used in management information system, but the extent to which information use should be computerized. The concept of a user-machine system implies that some tasks are best performed by humans, while others are best done by machine. The user of an MIS is any person responsible for entering input data, instructing the system, or utilizing the information output of the system. For many problems, the user and the computer form a combined system with results obtained through a set of interactions between the computer and the user. User-machine interaction is facilitated by operation in which the user’s input-output device (usually a visual display terminal) is connected to the computer. The computer can be a personal computer serving only one user or a large computer that

企业数据建模外文翻译文献

企业数据建模外文翻译文献 (文档含中英文对照即英文原文和中文翻译) 翻译: 信息系统开发和数据库开发 在许多组织中,数据库开发是从企业数据建模开始的,企业数据建模确定了组织数据库的范围和一般内容。这一步骤通常发生在一个组织进行信息系统规划的过程中,它的目的是为组织数据创建一个整体的描述或解释,而不是设计一个特定的数据库。一个特定的数据库为一个或多个信息系统提供数据,而企业数据模型(可能包含许多数据库)描述了由组织维护的数据的范围。在企业数据建模时,你审查当前的系统,分析需要支持的业务领域的本质,描述需要进一步抽象的数据,并且规划一个或多个数据库开发项目。图1显示松谷家具公司的企业数据模型的一个部分。 1.1 信息系统体系结构 如图1所示,高级的数据模型仅仅是总体信息系统体系结构(ISA)一个部分或一个组

织信息系统的蓝图。在信息系统规划期间,你可以建立一个企业数据模型作为整个信息系统体系结构的一部分。根据Zachman(1987)、Sowa和Zachman(1992)的观点,一个信息系统体系结构由以下6个关键部分组成: 数据(如图1所示,但是也有其他的表示方法)。 操纵数据的处理(着系可以用数据流图、带方法的对象模型或者其他符号表示)。 网络,它在组织内并在组织与它的主要业务伙伴之间传输数据(它可以通过网络连接和拓扑图来显示)。 人,人执行处理并且是数据和信息的来源和接收者(人在过程模型中显示为数据的发送者和接收者)。 执行过程的事件和时间点(它们可以用状态转换图和其他的方式来显示)。 事件的原因和数据处理的规则(经常以文本形式显示,但是也存在一些用于规划的图表工具,如决策表)。 1.2 信息工程 信息系统的规划者按照信息系统规划的特定方法开发出信息系统的体系结构。信息工程是一种正式的和流行的方法。信息工程是一种面向数据的创建和维护信息系统的方法。因为信息工程是面向数据的,所以当你开始理解数据库是怎样被标识和定义时,信息工程的一种简洁的解释是非常有帮助的。信息工程遵循自顶向下规划的方法,其中,特定的信息系统从对信息需求的广泛理解中推导出来(例如,我们需要关于顾客、产品、供应商、销售员和加工中心的数据),而不是合并许多详尽的信息请求(如一个订单输入屏幕或按照地域报告的销售汇总)。自顶向下规划可使开发人员更全面地规划信息系统,提供一种考虑系统组件集成的方法,增进对信息系统与业务目标的关系的理解,加深对信息系统在整个组织中的影响的理解。 信息工程包括四个步骤:规划、分析、设计和实现。信息工程的规划阶段产生信息系统体系结构,包括企业数据模型。 1.3 信息系统规划 信息系统规划的目标是使信息技术与组织的业务策略紧密结合,这种结合对于从信息系统和技术的投资中获取最大利益是非常重要的。正如表1所描述的那样,信息工程方法的规划阶段包括3个步骤,我们在后续的3个小节中讨论它们。 1.确定关键性的规划因素

企业人力资源管理系统分析与设计 外文翻译

Enterprise Human Resources Management System Design And Implementation Abstract: Human resource management system is the core content of modern enterprise management. With the rapid development of the computer information technology and unprecedented prevalence of electronic commerce mode,the competition between enterprises is turning from visible economic markets to the network. Developing the human resource management system supported by computer technology,network technology and information technology can not only improve the skill of human resource management and the efficiency of the enterprises but also make human resource management modern and decision sciencefic,Modern human resource management uses B/S mode to avoid C/S modes short coming of difficult in maintdning and reusing.According to the functional requirements of the actual project,this article specificly state the analysis of system,the general desigin of the system,the detail design of system and the practice of the system. The development of the system is the practice of MVC design ideas, maing using the Jsp+Servlet+JavaBean form of development.Jsp is the practice of MVC design ideas’view,in charge of receiving/responding the request of the customer.Servlet mainly responsible for the core business control of the whole system is the practice of the vontroller of MVC design idea to take charge of the statistics and rules of the whole system. In the practice of the system, somr open-source projrcts,such as the Ajax technique,JfreChart statements,fileupload technology,has been used. Using the modern human resource management theropy and analysising the actual situation, comparing the current situation of human resource management system, a huaman resource contents of management system basied on the Internet/Intranet has been designed. The main management,attendance management training more efficient statistics. Keywords:human resource management; B/S mode; Open-source projects; MVC mode. 摘要 人力资源管理系统是现代企业管理的核心内容。随着计算机信息技术的高速发展,电子商务模式的空前盛行,企业之间的竞争也从有形的经济市场转向了网络。开发以计算机技术、网络技术、信息技术支持的现代人力资源管理系统,既能提高企业人力资源管理的技术含量和企业的办事效率,也能使人力资源管理能够进入现代化、决策科学化的进程。现代人力资源管理系统采用了B/S模式,可以避免C/S模式的重用性差、维护难度高的缺点和

外文文献翻译 An Introduction to Database Management System

英文翻译 数据库管理系统的介绍 Raghu Ramakrishnan 数据库(database,有时被拼作data base)又称为电子数据库,是专门组织起来的一组数据或信息,其目的是为了便于计算机快速查询及检索。数据库的结构是专门设计的,在各种数据处理操作命令的支持下,可以简化数据的存储、检索、修改和删除。数据库可以存储在磁盘、磁带、光盘或其他辅助存储设备上。 数据库由一个或一套文件组成,其中的信息可以分解为记录,每一条记录又包含一个或多个字段(或称为域)。字段是数据存取的基本单位。数据库用于描述实体,其中的一个字段通常表示与实体的某一属性相关的信息。通过关键字以及各种分类(排序)命令,用户可以对多条记录的字段进行查询,重新整理,分组或选择,以实体对某一类数据的检索,也可以生成报表。 所有数据库(除最简单的)中都有复杂的数据关系及其链接。处理与创建,访问以及维护数据库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其用户间建立接口。(这些用户可以是应用程序员,管理员及其他需要信息的人员和各种操作系统程序)DBMS可组织、处理和表示从数据库中选出的数据元。该功能使决策者能搜索、探查和查询数据库的内容,从而对正规报告中没有的,不再出现的且无法预料的问题做出回答。这些问题最初可能是模糊的并且(或者)是定义不恰当的,但是人们可以浏览数据库直到获得所需的信息。简言之,DBMS将“管理”存储的数据项和从公共数据库中汇集所需的数据项用以回答非程序员的询问。 DBMS由3个主要部分组成:(1)存储子系统,用来存储和检索文件中的数据;(2)建模和操作子系统,提供组织数据以及添加、删除、维护、更新数据的方法;(3)用户和DBMS之间的接口。在提高数据库管理系统的价值和有效性方面正在展现以下一些重要发展趋势: 1.管理人员需要最新的信息以做出有效的决策。 2.客户需要越来越复杂的信息服务以及更多的有关其订单,发票和账号的当前信息。

餐饮管理系统外文翻译文献

餐饮管理系统外文翻译文献(文档含中英文对照即英文原文和中文翻译) 英文: 1、China food industry development prospects analysis The catering industry in China as the tertiary industry is a traditional service industries, experienced reforming and opening starts, quantitative expansion, scale chain development and brand promotion strategy of 4phase, made make a spurt of progress in the development of. At present, the country has4 millions catering outlets. 2005/2006annual Chinese top 100 catering enterprises with total assets of about thirty-two billion yuan, total profit of about six billion yuan, employees about eight hundred thousand people, respectively, over the same period last year increased40.38%,28.84% and33.33% higher than that of the whole society, the catering industry average growth level. China's reform and opening up has gone through ups and downs in the30year, in the30 years of reforming and opening of China's catering industry along with the tide of reform has undergone three leap type development. In the past 30 years, China has experienced from fast food restaurants grabs beach China market to SARS impact, then to food safety ( tonyred event, apple events ), Chinese food and beverage industry in the impact, achieve sales growth.

图书管理系统外文翻译

毕业设计(论文)外文资料翻译设计(论文)题目图书管理系统 院系计算机工程系 专业计算机科学与技术 年级 学生学号1040520007 学生姓名bianhaiwei 外文出处CHINA-USA Business Review

Combining JSP and Servlets The technology of JSP and Servlet is the most important technology which use Java technology to exploit request of server, and it is also the standard which exploit business application .Java developers prefer to use it for a variety of reasons, one of which is already familiar with the Java language for the development of this technology are easy to learn Java to the other is "a preparation, run everywhere" to bring the concept of Web applications, To achieve a "one-prepared everywhere realized." And more importantly, if followed some of the principles of good design, it can be said of separating and content to create high-quality, reusable, easy to maintain and modify the application. For example, if the document in HTML embedded Java code too much (script), will lead the developed application is extremely complex, difficult to read, it is not easy reuse, but also for future maintenance and modification will also cause difficulties. In fact, CSDN the JSP / Servlet forum, can often see some questions, the code is very long, can logic is not very clear, a large number of HTML and Java code mixed together. This is the random development of the defects. Early dynamic pages mainly CGI (Common Gateway Interface, public Gateway Interface) technology, you can use different languages of the CGI programs, such as VB, C / C + + or Delphi, and so on. Though the technology of CGI is developed and powerful, because of difficulties in programming, and low efficiency, modify complex shortcomings,

外文文献之数据库信息管理系统简介

Introduction to database information management system The database is stored together a collection of the relevant data, the data is structured, non-harmful or unnecessary redundancy, and for a variety of application services, data storage independent of the use of its procedures; insert new data on the database , revised, and the original data can be retrieved by a common and can be controlled manner. When a system in the structure of a number of entirely separate from the database, the system includes a "database collection." Database management system (database management system) is a manipulation and large-scale database management software is being used to set up, use and maintenance of the database, or dbms. Its unified database management and control so as to ensure database security and integrity. Dbms users access data in the database, the database administrator through dbms database maintenance work. It provides a variety of functions, allows multiple applications and users use different methods at the same time or different time to build, modify, and asked whether the database. It allows users to easily manipulate data definition and maintenance of data security and integrity, as well as the multi-user concurrency control and the restoration of the database. Using the database can bring many benefits: such as reducing data redundancy, thus saving the data storage space; to achieve full sharing of data resources, and so on. In addition, the database technology also provides users with a very simple means to enable users to easily use the preparation of the database applications. Especially in recent years introduced micro-computer relational database management system dBASELL, intuitive operation, the use of flexible, convenient programming environment to extensive (generally 16 machine, such as IBM / PC / XT, China Great Wall 0520, and other species can run software), data-processing capacity strong. Database in our country are being more and more widely used, will be a powerful tool of economic management. The database is through the database management system (DBMS-DATA BASE MANAGEMENT SYSTEM) software for data storage, management and use of dBASELL is a database management system software. Information management system is the use of data acquisition and transmission technology, computer network technology, database construction, multimedia

数据库管理系统外文翻译

附录:英文资料及翻译 英文原文: DATA BASE MANAGEMENT SYSTEMS You know that a data 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. there’s nothing new about data bases-early ones were chiseled in st-one, penned on scrolls ,and written on index cards. but mow data bases are commonly recorded on magnetizeable media, and computer programs are required to perform the necessary storage ad retrieval operations. The system software package that handles the difficult tasks associated with creating , accessing ,and maintaining data base records is in a DBMS package establish an interface between the data base itself and the users of the data base . ( 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 data base .this capability enables decision makers to search . probe ,and query data base 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 data base until they have the needed information . in short, the DBMS will “manage ”the stored data items and assemble the needed items from the common data base 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 information. The availability of a DBMS ,however, offers users a much faster alternative communications path (see figure). Sequential, direct, and other file processing approaches are used to organize and structure data in single files .but a DBMS is able to integrate data elements from several files to answer specific user inquiries fir information. This means that the DBMS is able to integrate data elements from

外文翻译《企业人事管理系统》资料

The business enterprise personal management system The 21st century the most intense competition should belong to talents competition, a multi-discipline knowledge of compound talents is probably a enterprises to grow an indispensable part of the important factor. Therefore Human Resource has become the most important Resource of enterprises, the Human resources Management, Human Resource Management (HRM) has become the modern enterprise Management work in one important content of. And in the human resources management of basic work is personnel file management. For corporations, staff personnel files of not only can make the managers in a certain extent master the basic personnel they hire personnel information, but also for the enterprise human resources supervisory work to provide relevant personnel information data support. For example: enterprise make staff recruitment and training plans, reasonable use of personnel, etc. Therefore, the enterprise personnel file management work quality not only can directly affect the enterprise human resources management, and will indirectly affect the whole enterprise management. With the development of society, the progress of science and technology, the application of computer in social fields are widely used, more and more people both felt use computer different management science and convenient; To realize the management information system to manage the importance of work. Management Information System, Management Information System (MIS), is an enterprise is the production and operation of various internal and external Information for the collection, processing, sorting, transfer, and orderly storage and used in the Management and decision-making, is the enterprise efficiency of Information System. It can make the enterprise more timely, accurate, comprehensive and detailed understanding the information needed data. At the same time management information system for various information data of further processing, can make the enterprise of the leadership of production, marketing, management decision-making basis for more fully and is more reasonable and scientific, Thus for society to create more value for the development of enterprises to create more opportunities. In addition, the management information system can make the enterprise management more scientific, rationalization and institutionalized, standardization, For the enterprise's management level up to a new stage, For the enterprise the continuous, healthy and stable development of the lay solid foundation. Personnel file management system is the typical information management

相关主题
文本预览
相关文档 最新文档