【正文】 管理信息系統(tǒng)對(duì)于一個(gè)數(shù)據(jù)庫(kù)的需要將在下面被談?wù)?。 即使應(yīng)用系統(tǒng)是一次一個(gè)的被執(zhí)行 ， 他們的設(shè)計(jì)可以由整體計(jì)劃指導(dǎo) ， 確定他們?cè)趺捶掀渌墓ぷ?。 但是 ， 用戶需要能夠詳細(xì)說明他們的 信息要求；對(duì)計(jì)算機(jī)的一些理解、信息的本質(zhì) ， 和對(duì)各種各樣管理功能的利用將幫助用戶完成任務(wù) 。 用戶機(jī)器的相互作用是由用戶連接在計(jì)算機(jī)上的輸入 輸出設(shè)備（通常是一個(gè)視覺顯示終端）推動(dòng)的 。 該信息系統(tǒng)利用計(jì)算機(jī)硬件和軟件；手工處理程序；模擬分析法計(jì)劃、控制和決策；和數(shù)據(jù)庫(kù) 。 第一 ， 是參數(shù)文本 的概念 ， 即設(shè)計(jì)和任一種文本系統(tǒng) ， 其行為可能通過調(diào)節(jié)系統(tǒng)參數(shù)而改制 。 在傳統(tǒng)數(shù)據(jù)庫(kù)系統(tǒng)中為自動(dòng)并行控制 ， 通過使用鎖定而實(shí)行串行 ， 并為了從系統(tǒng)失靈中自動(dòng)恢復(fù)而聯(lián)機(jī) 。 由于數(shù)據(jù)容量的增長(zhǎng)是一種發(fā)展趨勢(shì) ， 所以應(yīng)該考慮在較大的權(quán)器上獲得相同或相容的軟件 。 一個(gè)事先不了解計(jì)算機(jī)知識(shí)的用戶能夠使用該系統(tǒng)來儲(chǔ)存?zhèn)€人和職業(yè)數(shù)據(jù) ， 檢索和執(zhí)行有關(guān)處理 。 軟件也就不那么復(fù)雜 。 如果數(shù)據(jù)庫(kù)管理系統(tǒng)提供一種方法來相互作用地進(jìn)入和修改數(shù)據(jù)庫(kù) ， 同時(shí)查詢數(shù)據(jù)庫(kù) ， 這種方法就為管理個(gè)人數(shù)據(jù)庫(kù)創(chuàng)造了條件 。 （這些用戶可以是應(yīng)用程序員、管理員、及其他需要信息的人員和各種操作系統(tǒng)程序） 。 However, information is generally defined as data that is meaningful or useful to the recipient. Data items are therefore the raw material for producing information. The underlying concept of a database is that data needs to be managed in order to be available for processing and have appropriate quality. This data management includes both software and organization. The software to create and manage a database is a database management system. When all access to any use of database is controlled through a database management syste m, all applications utilizing a particular data item access the same data item which is stored in only one place. A single updating of the data item updates it for all uses. Integration through a database management system requires a central authority for the database. The data can be stored in one central puter or dispersed among several puters。s own programming language. That is not the same as users who create and manage personal files that are not part of the mainstream pany system. Transaction Management of Database The objective of longduration transactions is to model longduration, interactive Database access sessions in application environments. The fundamental assumption about shortduration 7 of transactions that underlies the traditional model of transactions is inappropriate for longduration transactions. The implementation of the traditional model of transactions may cause intolerably long waits when transactions aleph to acquire locks before accessing data, and may also cause a large amount of work to be lost when transactions are backed out in response to userinitiated aborts or system failure situations. The objective of a transaction model is to provide a rigorous basis for automatically enforcing criterion for database consistency for a set of multiple concurrent read and write accesses to the database in the presence of potential system failure situations. The consistency criterion adopted for traditional transactions is the notion of scrializability. Scrializability is enforced in conventional database systems through the use of locking for automatic concurrency control, and logging for automatic recovery from system failure situations. A “transaction” that doesn’t provide a basis for automatically enforcing database consistency is not really a transaction. To be sure, a longduration transaction need not adopt serializability as its consistency criterion. However, there must be some consistcricy criterion. Version System Management of Database Despite a large number of proposals on version support in the context of puter aided design and software engineering, the absence of a consensus on version semantics has been a key impediment to version support in database systems. Because of the differences between files and databases, it is intuitively clear that the model of versions in database systems cannot be as simple as that adopted in file systems to support software databases, it may be necessary to manage not only versions of single objects (. a software module, document, but also versions of a collection of objects (. a pound document, a user manual, etc. and perhaps even versions of the schema of database (. a table or a class, a collection of tables or classes). Broadly, there are three directions of research and development in versioning. First is the notion of a parameterized versioning, that is, designing and implementing a versioning system whose behavior may be tailored by adjusting system parameters This may be the only viable approach, in view of the fact that there are various plausible choices for virtually every single aspect of second is to revisit these plausible choices for every aspect of versioning, with the view to discarding some of themes either impractical or flawed. The third is the investigation into the semantics and implementation of versioning collections of objects and of versioning the database. 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 puterbased information processing system 8 which supports the operations, management, and decisionmaking functions of an organization. This text uses “MIS” because it is descriptive and generally understood。但 C從一開始就使用 .NET，對(duì) .NET 特性的支持不僅是完整的，而且提供了比其他語(yǔ)言更合適的語(yǔ)法。 ● 可以用用戶 定義的特性來標(biāo)記類或方法。從語(yǔ)法上看， C非常類似于 C++和 Java，許多關(guān)鍵字都是相同的， C也使用類似于 C++和 Java的塊結(jié) 構(gòu)，并用括號(hào) (｛｝ )來標(biāo)記代碼塊，用分號(hào)分隔各行語(yǔ)句。其結(jié)果是在 Windows 中，該語(yǔ)言成為了一種非常雜亂的語(yǔ)言。 對(duì)于 Visual Basic 來說，它的主要優(yōu)點(diǎn)是很容易理解，許多編程工作都很容易完成，基本上隱藏了 Windows API 和 COM 組件結(jié)構(gòu)的內(nèi)涵。其缺點(diǎn)是 Visual Basic 從來沒有實(shí)現(xiàn)真正意義上的面向?qū)ο?，所以大型?yīng)用程序很難分解和維護(hù)。讓一個(gè)C++開發(fā)人員說說字符串有多少個(gè)定義方式就可以說明這一點(diǎn)： char*、 LPTSTR、 string、CString (MFC 版本 )、 CString (WTL 版本 )、 wchar_t*和 OLECHAR*等。對(duì) C代碼的第一印象是它非常類似于 C++或 Java 代碼。這可以用于文檔說明，對(duì)編譯有一定的影響 (例如，把方法標(biāo)記為只在調(diào)試時(shí)編譯 )。 C語(yǔ)言本身非常類似于 Java，但其中有一些改進(jìn)，因?yàn)?Java 并不是為應(yīng)用于 .NET 環(huán)境而設(shè)計(jì)的。 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, usermac