管理信息系統(tǒng)外文翻譯 (2)

1、<p>　　東XXXXXXX計算機學(xué)院</p><p>　　畢業(yè)設(shè)計（論文）外文文獻翻譯</p><p>　　Management Information System</p><p>　　It is the MIS(Management Information System ) that we constantly say that the mana

2、gement information system , and is living to emphasize the administration , and emphasizes that it changes into more and more significantly and more and more is universalized in the contemporary community of message . MI

3、S is a fresh branch of learning, and it leaped over several territories, and for instance administers scientific knowledge, system science, operational research, statistic along with calculating m</p><p>　　1

4、.The Management Information System Summary</p><p>　　20 centuries, in the wake of the flourishing development of whole world economy, numerous economists propose the fresh administration theory one by one. X

5、i Men propose the administration and was dependent on idea to message and decision of strategic importance in the 50’s 20 centuries. The dimension of simultaneous stage is admitted issuing cybernetics, and he thinks that

6、 the administration is a control procedure. In 1958, Ger. write the lid: “ the administration shall obtain without delay with </p><p>　　In 1970, Walter T.Kennevan give administration that has raised the only

7、 a short while ago information system term to get off a definition: “ either the cover of the book shape with the discount, is living appropriately time to director, staff member along with the outside world personnel st

8、aff supplies the past and now and message that internal forecasting the approaching relevant business reaches such environment, in order to assist they make a strategic decision”. Is living in this definition </p>

9、<p>　　In 1985, admonishing information system originator, title Buddhist nun Su Da university administration professor Gordon B.Davis give the management information system relatively integrated definition, in imme

10、diate future “ administer the information system is one use calculating machine software and hardware resources along with data bank man - the engine system. </p><p>　　It be able to supply message support bu

11、siness either organization operation, administration or the decision making function. Comprehensive directions of this definition management information system target and meritorious service capacity and component, but a

12、lso make known the management information system to be living the level that attains at that time. </p><p>　　1.1 The Developing History of MIS </p><p>　　The management information system is livi

13、ng the most primarily phase is counting the system, the substance which researched is the regular pattern on face between the incremental data, it what may separate into the data being mutually related and more not being

14、 mutually related series, afterwards act as the data conversion to message. </p><p>　　The second stage is the data are replaced the system, and it is that the SABRE that the American airline company put up t

15、o in the 50’s 20 centuries subscribes to book the bank note system that such type stands for. It possess 1008 bank note booking spots, and may access 600000 traveler keep the minutes and 27000 flight segments record. Its

16、 operation is comparatively more complex, and is living whatever one “spot ”wholly to check whether to be the free place up some one flight numbers. Yet throug</p><p>　　The third phase is the status reports

17、system, and it may separate into manufacture state speech and service state and make known and research the systems such as status reports and so on. Its type stands for the production control system that is the IBM corp

18、oration to the for instance manufacture state speech system. As is known to all, the calculating machine corporation that the IBM corporation is the largest on the world, in 1964 it given birth to middle-sized calculatin

19、g machine IBM360 and c</p><p>　　system CMIS and runs and succeeds very much, the past needs 15 weeks work, that system merely may be completed in the way of 3 weeks. </p><p>　　It is the data han

20、dling system that the status reports system still possess one kind of shape , and that it is used for handles the everyday professional work to make known with manufacture , and stress rests with by the handwork task au

21、tomation , and lifts the effectiveness with saves the labor power . The data handling system ordinarily can not supply decision of strategic importance message. </p><p>　　Last phase is the support systems ma

22、ke a strategic decision, and it is the information system being used for supplementary making a strategic decision. That system may program and the analysis scheme, and goes over key and the error solve a problem. Its pr

23、oper better person-machine dialogue means, may with not particularly the personnel staff who have an intimate knowledge of the calculating machine hold conversation. It ordinarily consists of some pattern so as to come i

24、nto being decision of st</p><p>　　1.2 The Application of Management Information System</p><p>　　The management information system is used to the most base work, like dump report form, calculati

25、on pay and occurrences in human tubes and so on, and then developing up business financial affairs administrations and inventory control and so on individual event operational control , this pertains to the electron data

26、 handling ( EDP Data Processing ) system . When establish the business data bank, thereby possess the calculating machine electric network to attain data sharing queen , the slave sys</p><p>　　There is the p

27、art application that few business start MIS inner place the limit of the world at the early days of being living in the 70’s 20 centuries. Up at the moment, MIS is living, and there be the appropriate </p><p&g

28、t;　　Popularization rate in every state nation in world, and nearly covered that every profession reaches every department. </p><p>　　1.3 The Direction of MIS Development</p><p>　　Close 20 curta

29、ins; external grand duke takes charge of having arisen3 kinds of alternations: </p><p>　　A.Paying special attention to the administration being emphasized to establishing MIS’s system, and causing the admin

30、istration technique head for the ageing. </p><p>　　B.The message is the decision of strategic importance foundation, and MIS supplies the message service in the interest of director at all times. </p>

31、<p>　　C.Director causes such management program getting in touch with together with the concrete professional work maneuver by means of MIS. not merely big-and-middle-sized business universally establish MIS some

32、 small-size business also not exceptions of self, universally establish the communal data network, like the electronic mail and electron data exchange and so on, MIS supplied the well support environment to the applicati

33、on of Intranet’s technique to speedily developing of INTERNET especially </p><p>　　Through international technique development tendency is see, in the 90’s 20 centuries had arisen some kinds of brand-new adm

34、inistration technique.</p><p>　　1.Business Processes Rebuild (BPR)</p><p>　　A business should value correctly time and produce quality, manufacturing cost and technical service and so on severa

35、l section administrations, grip at the moment organization and the process compose once more,andcompletes that meritorious service capacity integrationist, operation processization and organization form fluctuation. Shal

36、l act as the service veer of middle layer management personnel staff the decision of strategic importance of the director service?</p><p>　　2.Intelligentization Decision Support System (IDSS)</p><

37、;p>　　The intelligentization decision of strategic importance support system was sufficiently consider demand and the work distinguishing feature of business higher level personnel staff. </p><p>　　3.Lean

38、 Production (LP) </p><p>　　Application give birth to on time, comprehensive quality control and parallel project that picked amount is given birth to and so on the technique, the utmost product design cuttin

39、g down and production cycle, raise produce quality and cuts down the reproduced goods to reserve, and is living in the manufacture promote corps essence, in order to meet the demand that client continuously changes. <

40、/p><p>　　4.Agile Manufacture (AM) </p><p>　　One kind of business administration pattern that possess the vision, such distinguishing feature is workers and staff members’ quality is high, and the

41、organization simplifies and the multi-purpose group effectiveness GAO message loading is agile and answers client requires swiftly. </p><p>　　2.The Effect To The Business Administration of MIS Development&

42、lt;/p><p>　　The effect to the business administration of the management information system development is administered the change to business and business administration of information system development and co

43、me into being and is coming into being the far-reaching effect with. </p><p>　　Decision of strategic importance, particularly strategic decision-making may be assisted by the administration information syste

44、m, and its good or bad directly affects living and the development up the business. The MIS is impeding the orientation development that the administration means one another unites through quality and ration. This expres

45、s to utilize the administration in the calculation with the different mathematical model the problem in the quantitative analysis business. </p><p>　　The past administer that the problem is diffi

46、cult to test, but MIS may unite the administration necessaries, and supply the sufficient data, and simulates to produce the term in the interest of the administration. </p><p>　　In the wake of the developme

47、nt of MIS, much business sit up the decentralized message concentration to establish the information system ministry of directly under director, and the chief of information system ministry is ordinarily in the interest

48、of assistant manager’s grade. After the authority of business is centralized up high-quality administration personnel staff’s hand, as if causing much sections office work decrease, hence someone prophesy, middle layer m

49、anagement shall vanish. In reali</p><p>　　This is for, although the middle layer management personnel staff getting off exonerate out through loaded down with trivial details daily routine, yet needs them to

50、 analyses researching work in the way of even more energy, lift further admonishing the decision of strategic importance level. In the wake of the development of MIS, the business continuously adds to the demand of high

51、technique a talented person, but the scarce thing of capability shall be washed out gradually. This compels people </p><p>　　The wake of the news dispatch and electric network and file transmission system de

52、velopment, business staff member is on duty in many being living incomparably either the home. Having caused that corporation save the expenses enormously, the work efficiency obviously moves upward American Rank Zeros c

53、orporation the office system on the net, in the interest of the creativity of raise office personnel staff was produced the advantageous term. </p><p>　　At the moment many countries are fermenting one kind o

54、f more well-developed manufacturing industry strategy, and become quickly manufacturing the business. It completely on the basis of the user requirement organization design together with manufacture, may carry on the lar

55、ge-scale cooperation in the interest of identical produce by means of the business that the flow was shifted the distinct districts, and by means of the once more programming to the machinery with to the resources and th

56、e reor</p><p>　　The management information system is towards the self-adoption and Self-learning orientation development, the decision procedure of imitation man who is be able to be better. Some entrepreneu

57、rs of the west vainly hope that consummate MIS is encircles the magic drug to govern the business all kinds of diseases; Yet also someone says, and what it is too many is dependent on the defeat that MIS be able to cause

58、 on the administration. It is adaptable each other to comprehend the effect to the busine</p><p>　　The Source Of Article： Russ Basiura, Mike Batongbacal</p><p><b>　　管理信息系統(tǒng)</b></p&

59、gt;<p>　　管理信息系統(tǒng)就是我們常說的MIS(Management Information System), 在強調(diào)管理，強調(diào)信息的現(xiàn)代社會中它變得越來越重要、越來越普及。MIS是一門新的學(xué)科，它跨越了若干個領(lǐng)域，比如管理科學(xué)、系統(tǒng)科學(xué)、運籌學(xué)、統(tǒng)計學(xué)以及計算機科學(xué)。在這些學(xué)科的基礎(chǔ)上，形成信息收集和加工的方法，從而形成一個縱橫交織的系統(tǒng)。</p><p>　　1．管理信息系統(tǒng)概述</p

60、><p>　　20世紀(jì)，隨著全球經(jīng)濟的蓬勃發(fā)展，眾多經(jīng)濟學(xué)家紛紛提出了新的管理理論。20世紀(jì)50年代，西蒙提出管理依賴于信息和決策的思想。同時期的維娜發(fā)表了控制論，他認(rèn)為管理是一個控制過程。1958年，蓋爾寫到：“管理將以較低的成本得到及時的、準(zhǔn)確的信息，做到較好的控制”。這個時期，計算機開始用于會計工作。數(shù)據(jù)處理一詞已經(jīng)出現(xiàn)。</p><p>　　1970年，Walter T.Kenneva

61、n給剛剛出現(xiàn)的管理信息系統(tǒng)一詞下了一個定義：“以扣頭或書面的形式，在合適的時間向經(jīng)理、職員以及外界人員提供過去的、現(xiàn)在的、預(yù)測未來的有關(guān)企業(yè)內(nèi)部及其環(huán)境的信息，以幫助他們進行決策”。</p><p>　　在這個定義里強調(diào)了用信息支持決策，但并沒有強調(diào)應(yīng)用模型，沒有提到計算機的應(yīng)用。</p><p>　　1985年，管理信息系統(tǒng)的創(chuàng)始人，名尼蘇達大學(xué)的管理學(xué)教授Gordon B.Davis給

62、了管理信息系統(tǒng)一個較為完整的定義，即“管理信息系統(tǒng)是一個利用計算機軟硬件資源以及數(shù)據(jù)庫的人-機系統(tǒng)。它能提供信息支持企業(yè)或組織的運行、管理和決策功能?！?這個定義全面的說明了管理信息系統(tǒng)的目標(biāo)、功能和組成，而且反映了管理信息系統(tǒng)在當(dāng)時達到的水平。</p><p>　　1.1管理信息系統(tǒng)的發(fā)展歷史</p><p>　　管理信息系統(tǒng)在初級階段是統(tǒng)計系統(tǒng)，所研究的內(nèi)容是數(shù)量數(shù)據(jù)間表面的規(guī)律，它可

63、以把數(shù)據(jù)分成較相關(guān)和較不相關(guān)的組，然后把數(shù)據(jù)轉(zhuǎn)換為信息。</p><p>　　第二階段是數(shù)據(jù)更新系統(tǒng)，其典型代表是美國航空公司于20世紀(jì)50年代建成的SABRE預(yù)約訂票系統(tǒng)。它設(shè)有1008個訂票點，可以存取600000個旅客記錄和27000個飛行段記錄。它的操作比較復(fù)雜，在任何“點”都可以查到某一航班是否有空座位。但從概念上來講，它只是一個數(shù)據(jù)更新系統(tǒng)，比如它不能告訴你以現(xiàn)在的售票速度何時票將售完，從而采取補救措

64、施。因而它也是管理信息系統(tǒng)的低級階段。</p><p>　　第三階段是狀態(tài)報告系統(tǒng)，它可以分成生產(chǎn)狀況報告、服務(wù)狀態(tài)報告和研究狀態(tài)報告等系統(tǒng)。比如生產(chǎn)狀況報告系統(tǒng)，它的典型代表是IBM公司的生產(chǎn)管理系統(tǒng)。眾所周知，IBM公司是世界上最大的計算機公司，1964年它生產(chǎn)出中型計算機IBM360，使計算機的水平提高了一個臺階，但同時組織生產(chǎn)的管理工作卻大大復(fù)雜化了，一臺計算機又超過15000個不同的部件，每個部件又有若

65、干個元件，加之IBM的工廠遍及美國各地，不同的訂貨有不同的部件和不同的元件，必須指出什么工廠什么設(shè)備生產(chǎn)什么元件，因此不僅生產(chǎn)復(fù)雜，裝配、安裝和運輸都十分復(fù)雜。為了保證生產(chǎn)以及其他環(huán)節(jié)的順利進行，必須要有一個以計算機為基礎(chǔ)的生產(chǎn)狀態(tài)報告系統(tǒng)。因此同年IBM建立了先進管理系統(tǒng)AAS,它能進行450個業(yè)務(wù)的操作。1968年，公司又建立了公用制造信息系統(tǒng)CMIS,運行很成功，過去需要15周的工作，該系統(tǒng)只用3周就可以完成。狀態(tài)報告系統(tǒng)還有一種

66、形式是數(shù)據(jù)處理系統(tǒng)，它用來處理日常業(yè)務(wù)和生產(chǎn)報告，重點在于將手工作業(yè)自動化，提高效率和節(jié)省人力。數(shù)據(jù)處理系統(tǒng)一般不能提供決策信息。</p><p>　　最后的階段是決策支持系統(tǒng)，它是用來輔助決策的信息系統(tǒng)。該系統(tǒng)可以計劃、分析方案，審查解答和求解的誤差。它應(yīng)有較好的人-機對話方式，可以和不怎么熟悉計算機的人員通話。它一般包括一些模型用以產(chǎn)生決策信息，但不強調(diào)全面的管理功能。</p><p>

67、;　　1.2管理信息系統(tǒng)的應(yīng)用</p><p>　　管理信息系統(tǒng)起初應(yīng)用于最基礎(chǔ)的工作，如打印報表、計算工資、人事管等，進而發(fā)展到企業(yè)財務(wù)管理、庫存管理等單項業(yè)務(wù)管理，這屬于電子數(shù)據(jù)處理(EDP,Electroni9c Data Processing) 系統(tǒng)。當(dāng)建立了企業(yè)數(shù)據(jù)庫，有了計算機網(wǎng)絡(luò)從而達到數(shù)據(jù)共享后，從系統(tǒng)觀點出發(fā)，實施全局規(guī)劃和設(shè)計信息系統(tǒng)時，就達到了管理信息系統(tǒng)階段。隨著計算機技術(shù)的進步和人們對系

68、統(tǒng)的需求進一步提高，人們更加強調(diào)管理信息系統(tǒng)的階段。隨著計算機技術(shù)的進步和人們對系統(tǒng)的需求進一步提高，人們更加強調(diào)管理信息系統(tǒng)能否支持企業(yè)高層領(lǐng)導(dǎo)的決策這一功能，更側(cè)重于企業(yè)外部信息的收集、綜合數(shù)據(jù)庫、模型庫、方法庫、和其它人工智能工具能否直接面向決策者，這是決策支持系統(tǒng)(DDS)的任務(wù)。</p><p>　　在20世紀(jì)70年代初期，世界范圍內(nèi)有少數(shù)企業(yè)開始MIS的局部應(yīng)用。到目前，MIS在世界各國已經(jīng)有了相當(dāng)?shù)?/p>

69、普及率，幾乎覆蓋了各個行業(yè)及各部門。</p><p>　　1.3管理信息系統(tǒng)的發(fā)展方向</p><p>　　近20年間，國外大公司出現(xiàn)了3種變化：</p><p>　　抓管理著重于建立MIS系統(tǒng)，使管理技術(shù)走向成熟。</p><p>　　信息是決策的依據(jù)，MIS隨時為經(jīng)理提供信息服務(wù)。</p><p>　　經(jīng)理通過MI

70、S使其經(jīng)營計劃和具體的業(yè)務(wù)活動聯(lián)系在一起。</p><p>　　由于以上的變化。MIS應(yīng)用得到了迅速的發(fā)展。不僅大中型企業(yè)普遍建立了自己的MIS,一些小型企業(yè)也不例外，普遍建立了公用數(shù)據(jù)網(wǎng)絡(luò)，如電子郵件、電子數(shù)據(jù)交換等，尤其是近年來INTERNET的飛速發(fā)展，INTRANET技術(shù)的應(yīng)用，為企業(yè)MIS提供了良好的支持環(huán)境。</p><p>　　從國際技術(shù)發(fā)展趨勢看，20世紀(jì)90年代出現(xiàn)了幾種

71、全新的管理技術(shù)</p><p>　　1.企業(yè)過程重組(BPR)</p><p>　　一個企業(yè)應(yīng)該重視對時間、產(chǎn)品質(zhì)量、生產(chǎn)成本和技術(shù)服務(wù)等幾個部分的管理，把目前的機構(gòu)和過程重新組合，做到功能集成化、運營過程化、機構(gòu)組織扁平化。</p><p>　　2.智能化決策支持系統(tǒng)(IDDS)</p><p>　　充分考慮了企業(yè)高層人員的要求和工作特點，

72、將把中層管理人員的服務(wù)轉(zhuǎn)向為經(jīng)理的決策服務(wù)。</p><p>　　3.精量生產(chǎn)(LP)</p><p>　　應(yīng)用準(zhǔn)時生產(chǎn)、全面質(zhì)量管理、并行工程等技術(shù)，最大限度的縮短產(chǎn)品設(shè)計和生產(chǎn)周期、提高產(chǎn)品質(zhì)量、降低再制品庫存，并在生產(chǎn)中提倡團隊精神，以滿足客戶不斷變化的需求。</p><p>　　4.靈捷制造(AM)</p><p>　　一種有遠(yuǎn)見的企

73、業(yè)管理模式，其特點是職工素質(zhì)高，組織機構(gòu)精簡、多功能小組效率高、信息存放靈活、響應(yīng)客戶要求迅速。</p><p>　　2.理信息系統(tǒng)的發(fā)展對企業(yè)管理的影響</p><p>　　管理信息系統(tǒng)的發(fā)展對企業(yè)和企業(yè)管理的變革產(chǎn)生了和正在產(chǎn)生著深遠(yuǎn)的影響。管理信息系統(tǒng)可以輔助決策，特別是戰(zhàn)略決策，它的好壞直接影響到企業(yè)的生存和發(fā)展。MIS正在促使管理方法由定性和定量相結(jié)合的方向發(fā)展。這表現(xiàn)在管理中運

74、用預(yù)測和各種數(shù)學(xué)模型來定量分析企業(yè)中的問題。過去管理問題難以進行試驗，而MIS則可以結(jié)合管理需要，提供充分的數(shù)據(jù)，為管理模擬創(chuàng)造條件。</p><p>　　隨著MIS的發(fā)展，許多企業(yè)把分散的信息集中起來成立了直屬經(jīng)理的信息系統(tǒng)部，信息系統(tǒng)部的負(fù)責(zé)人一般為副經(jīng)理級。企業(yè)的權(quán)力集中到高級管理人員手中以后，似乎使許多科室的工作減少了，因此有人預(yù)言，中層管理將消失。實際上，再現(xiàn)階段用了信息系統(tǒng)后中層管理不僅沒有減少，反而

75、稍有增加。這是因為，雖然中下層管理人員從繁瑣的事務(wù)性工作中解脫出來，但需要他們用更多的精力去分析研究工作，進一步提高管理決策水平。隨著MIS的發(fā)展，企業(yè)對高技術(shù)人才的需求不斷增加，而能力不足者將逐步被淘汰。這就迫使人們通過學(xué)習(xí)、培訓(xùn)，不斷提高個人素質(zhì)。隨著通訊、網(wǎng)絡(luò)和文檔傳輸系統(tǒng)的發(fā)展，企業(yè)職員可以在遠(yuǎn)地或家中上班。美國蘭克·施樂公司(Rank Zerox)的網(wǎng)上辦公系統(tǒng)，已經(jīng)使該公司大大節(jié)省了開支，工作效率明顯上升，為提高辦

76、公人員的創(chuàng)造性創(chuàng)造了優(yōu)越的條件。</p><p>　　目前許多國家正在醞釀一種更先進的制造業(yè)戰(zhàn)略，成為敏捷制造企業(yè)。它完全根據(jù)用戶需求來組織設(shè)計與生產(chǎn)，可以通過信息流調(diào)動不同地域的企業(yè)為同一個產(chǎn)品進行大協(xié)作，通過對機器的重新編程和對資源、人員的重新組織，構(gòu)成了一個新的制造系統(tǒng)，使得生產(chǎn)成本與批量幾乎無關(guān)。敏捷制造企業(yè)與用戶建立一個完全嶄新的戰(zhàn)略依存關(guān)系，將會引起產(chǎn)業(yè)結(jié)構(gòu)的又一次革命。</p><

77、;p>　　管理信息系統(tǒng)正在朝著自適應(yīng)、自學(xué)習(xí)的方向發(fā)展，也就是能更好的模擬人的決策過程。西方某些企業(yè)家夢想完善的MIS是包治企業(yè)百病的靈丹妙藥；但也有人說，過多的依賴MIS會導(dǎo)致管理上的失敗。了解MIS對企業(yè)的影響，有利于我們在開發(fā)和研究工作中，使企業(yè)的組織機構(gòu)、管理體制和管理方法更好的與MIS的發(fā)展相適應(yīng)，建立更有效的MIS。</p><p>　　文章的出處：《信息管理系統(tǒng)》，作者：Russ Basiur

78、a, Mike Batongbacal</p><p>　　A introduction to Database Management System</p><p>　　A database (sometimes spelled data base) is also called an electronic database , referring to any collection o

79、f 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 var

80、ious data-processing operations .Databases can be stored on magnetic disk or tape, optical disk, or some other secondary storage device.</p><p>　　A database consists of a file or a set of files. The informat

81、ion 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 at

82、tribute 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 particu&

83、lt;/p><p>　　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 maintain

84、ing 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 program

85、mers, managers and others with information needs, and various OS programs.)</p><p>　　A DBMS can organize, process, and present selected data elements form the database. This capability enables decision make

86、rs 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 defin

87、ed ,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 t</p><p>　　A database management system (DBMS) is

88、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

89、, 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;</p><p>　　Managers: who requir

90、e more up-to-data information to make effective decision</p><p>　　Customers: who demand increasingly sophisticated information services and more current information about the status of their orders, invoices

91、, and accounts.</p><p>　　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.</p><p>　　Org

92、anizations : that discover information has a strategic value; they utilize their database systems to gain an edge over their competitors.</p><p>　　The Database Model</p><p>　　A data model descri

93、bes 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

94、operation with which to add, delete, display, maintain, print, search, select, sort and update the data.</p><p>　　Hierarchical Model </p><p>　　The first database management systems used a hierar

95、chical 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

96、 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.</p><p>　　The hierarchical model was developed because hierarchical relationships a

97、re 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

98、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 d</p>&

99、lt;p>　　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 allowe