外文翻譯---數(shù)據(jù)庫管理

1、<p><b>　　英文資料翻譯</b></p><p>　　資料出處：From http://www.microsoft.com/china/ database</p><p><b>　　英文原文：</b></p><p>　　Database Management</p><p>　

2、　Database (sometimes spelled database) is also called an electronic database, referring to any collections of data, or information, that is specially organized for rapid search and retrieval by a computer. Databases are

3、structured to facilitate the storage, retrieval modification and deletion of data in conjunction with various data-processing operations. Database can be stored on magnetic disk or tape, optical disk, or some other secon

4、dary storage device.</p><p>　　A database consists of a file or a set of files. The information in the these files may be broken down into records, each of which consists of one or more fields are the basic u

5、nits 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, re

6、arrange, group, and select the fields in many records to retrieve or create reports on particular aggre</p><p>　　Database records and files must be organized to allow retrieval of the information. Early syst

7、em were arranged sequentially (i.e., alphabetically, numerically, or chronologically); the development of direct-access storage devices made possible random access to data via indexes. Queries are the main way users retr

8、ieve database information. Typically the user provides a string of characters, and the computer searches the database for a corresponding sequence and provides the source materials in wh</p><p>　　The many us

9、ers of a large database must be able to manipulate the information within it quickly at any given time. Moreover, large business and other organizations tend to build up many independent files containing related and even

10、 overlapping data, and their data, processing activities often require the linking of data from several files. Several different types of database management systems have been developed to support these requirements: fla

11、t, hierarchical, network, relational, and object-</p><p>　　In flat databases, records are organized according to a simple list of entities; many simple databases for personal computers are flat in structure.

12、 The records in hierarchical databases are organized in a treelike structure, with each level of records branching off into a set of smaller categories. Unlike hierarchical databases, which provide single links between s

13、ets of records at different levels, network databases create multiple linkages between sets by placing links, or pointers, to one se</p><p>　　The information in many databases consists of natural-language te

14、xts of documents; number-oriented database primarily contain information such as statistics, tables, financial data, and raw scientific and technical data. Small databases can be maintained on personal-computer systems a

15、nd may be used by individuals at home. These and larger databases have become increasingly important in business life. Typical commercial applications include airline reservations, production management, medical rec</

16、p><p>　　一、DBMS Structuring Techniques</p><p>　　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

17、 elements from several files to answer specific user inquiries for information. That is, the DBMS is able to structure and tie together the logically related data from several large files. </p><p>　　Logical

18、Structures. Identifying these logical relationships is a job of the data administrator. A data definition language is used for this purpose. The DBMS may then employ one of the following logical structuring techniques du

19、ring storage access, and retrieval operations.</p><p>　　List structures. In this logical approach, records are linked together by the use of pointers. A pointer is a data item in one record that identifies t

20、he storage location of another logically related record. Records in a customer master file, for example, will contain the name and address of each customer, and each record in this file is identified by an account number

21、. During an accounting period, a customer may buy a number of items on different days. Thus, the company may maintain an invoice </p><p>　　Hierarchical (tree) structures. In this logical approach, data units

22、 are structured in multiple levels that graphically resemble an “upside down” tree with the root at the top and the branches formed below. There’s a superior-subordinate relationship in a hierarchical (tree) structure. B

23、elow the single-root data component are subordinate elements or nodes, each of which, in turn, “own” one or more other elements (or none). Each element or branch in this structure below the root has only a single</p&g

24、t;<p>　　Network Structures. Unlike the tree approach, which does not permit the connection of branches, the network structure permits the connection of the nodes in a multidirectional manner. Thus, each node may h

25、ave several owners and may, in turn, own any number of other data units. Data management software permits the extraction of the needed information from such a structure by beginning with any record in a file.</p>

26、<p>　　Relational structures. A relational structure is made up of many tables. The data are stored in the form of “relations” in these tables. For example, relation tables could be established to link a college cour

27、se with the instructor of the course, and with the location of the class.</p><p>　　To find the name of the instructor and the location of the English class, the course/instructor relation is searched to get

28、the name (“Fitt”), and the course/location relation is a relatively new database structuring approach that’s expected to be widely implemented in the future.</p><p>　　Physical Structures. People visualize or

29、 structure data in logical ways for their own purposes. Thus, records R1 and R2 may always be logically linked and processed in sequence in one particular application. However, in a computer system it’s quite possible th

30、at these records that are logically contiguous in one application are not physically stored together. Rather, the physical structure of the records in media and hardware may depend not only on the I/O and storage devices

31、 and techniques used</p><p>　　二、Database Management Features of Oracle </p><p>　　Oracle includes many features that make the database easier to manage. We’ve divided the discussion in this secti

32、on into three categories: Oracle Enterprise Manager, add-on packs, backup and recovery.</p><p>　　1.Oracle Enterprise Manager</p><p>　　As part of every Database Server, Oracle provides the Oracle

33、 Enterprise Manager (EM), a database management tool framework with a graphical interface used to manage database users, instances, and features (such as replication) that can provide additional information about the Ora

34、cle environment.</p><p>　　Prior to the Oracle8i database, the EM software had to be installed on Windows 95/98 or NT-based systems and each repository could be accessed by only a single database manager at a

35、 time. Now you can use EM from a browser or load it onto Windows 95/98/2000 or NT-based systems. Multiple database administrators can access the EM repository at the same time. In the EM repository for Oracle9i, the supe

36、r administrator can define services that should be displayed on other administrators’ consoles, and</p><p>　　2. Add-on packs</p><p>　　Several optional add-on packs are available for Oracle, as d

37、escribed in the following sections. In addition to these database-management packs, management packs are available for Oracle Applications and for SAP R/3.</p><p>　　(1) standard Management Pack </p>&

38、lt;p>　　The Standard Management Pack for Oracle provides tools for the management of small Oracle databases (e.g., Oracle Server/Standard Edition). Features include support for performance monitoring of database conten

39、tion, I/O, load, memory use and instance metrics, session analysis, index tuning, and change investigation and tracking.</p><p>　　(2) Diagnostics Pack </p><p>　　You can use the Diagnostic Pack t

40、o monitor, diagnose, and maintain the health of Enterprise Edition databases, operating systems, and applications. With both historical and real-time analysis, you can automatically avoid problems before they occur. The

41、pack also provides capacity planning features that help you plan and track future system-resource requirements. </p><p>　　(3)Tuning Pack</p><p>　　With the Tuning Pack, you can optimise system pe

42、rformance by identifying and tuning Enterprise Edition databases and application bottlenecks such as inefficient SQL, poor data design, and the improper use of system resources. The pack can proactively discover tuning o

43、pportunities and automatically generate the analysis and required changes to tune the systems. </p><p>　　(4) Change Management Pack</p><p>　　The Change Management Pack helps eliminate errors and

44、 loss of data when upgrading Enterprise Edition databases to support new applications. It impact and complex dependencies associated with application changes and automatically perform database upgrades. Users can initiat

45、e changes with easy-to-use wizards that teach the systematic steps necessary to upgrade.</p><p>　　(5) Availability</p><p>　　Oracle Enterprise Manager can be used for managing Oracle Standard Edi

46、tion and/or Enterprise Edition. Additional functionality is provided by separate Diagnostics, Tuning, and Change Management Packs.</p><p>　　3. Backup and Recovery</p><p>　　As every database admi

47、nistrator knows, backing up a database is a rather mundane but necessary task. An improper backup makes recovery difficult, if not impossible. Unfortunately, people often realize the extreme importance of this everyday t

48、ask only when it is too late –usually after losing business-critical data due to a failure of a related system.</p><p>　　The following sections describe some products and techniques for performing database b

49、ackup operations.</p><p>　　(1) Recovery Manager</p><p>　　Typical backups include complete database backups (the most common type), database backups, control file backups, and recovery of the dat

50、abase. Previously, Oracle’s Enterprise Backup Utility (EBU) provided a similar solution on some platforms. However, RMAN, with its Recovery Catalog stored in an Oracle database, provides a much more complete solution. RM

51、AN can automatically locate, back up, restore, and recover databases, control files, and archived redo logs. RMAN for Oracle9i can restart back</p><p>　　(2) Incremental backup and recovery</p><p&g

52、t;　　RMAN can perform incremental backups of Enterprise Edition databases. Incremental backups back up only the blocks modified since the last backup of a datafile, tablespace, or database; thus, they’re smaller and faste

53、r than complete backups. RMAN can also perform point-in-time recovery, which allows the recovery of data until just prior to a undesirable event.</p><p>　　(3) Legato Storage Manager</p><p>　　Var

54、ious media-management software vendors support RMAN. Oracle bundles Legato Storage Manager with Oracle to provide media-management services, including the tracking of tape volumes, for up to four devices. RMAN interfaces

55、 automatically with the media-management software to request the mounting of tapes as needed for backup and recovery operations.</p><p>　　(4)Availability</p><p>　　While basic recovery facilities

56、 are available for both Oracle Standard Edition and Enterprise Edition, incremental backups have typically been limited to Enterprise Edition.</p><p>　　Data Independence </p><p>　　An important p

57、oint about database systems is that the database should exist independently of any of the specific applications. Traditional data processing applications are data dependent. COBOL programs contain file descriptions and r

58、ecord descriptions that carefully describe the format and characteristics of the data.</p><p>　　Users should be able to change the structure of the database without affecting the applications that use it. Fo

59、r example, suppose that the requirements of your applications change. A simple example would be expanding ZIP codes from five digits to nine digits. On a traditional approach using COBOL programs each individual COBOL ap

60、plication program that used that particular field would have to be changed, recompiled, and retested. The programs would be unable to recognize or access a file that had</p><p>　　Most database programs provi

61、de the ability to change the database structure by simply changing the ZIP code field and the data-entry form. In this case, data independence allows for minimal disruption of current and existing applications. Users can

62、 continue to work and can even ignore the nine-digit code if they choose. Eventually, the file will be converted to the new nine-digit ZIP code, but the ease with which the changeover takes place emphasizes the importanc

63、e of data independence.</p><p>　　Data Integrity</p><p>　　Data integrity refers to the accuracy, correctness, or validity of the data in the database. In a database system, data integrity means s

64、afeguarding the data against invalid alteration or destruction arise. The first has to do with many users accessing the database concurrently. For example, if thousands of travel agents and airline reservation clerks are

65、 accessing the database concurrently. For example, if thousands of travel agents and airline reservation clerks are accessing the same database</p><p>　　The second complication relates to hardwires, software

66、, or human error during the course of processing and involves database transactions treated as a single . For example, an agent booking an airline reservation involves several database updates (i.e., adding the passenger

67、’s name and address and updating the seats-available field), which comprise a single transaction. The database transaction is not considered to be completed until all updates have been completed; otherwise, none of the u

68、pdates</p><p>　　Data Security</p><p>　　Data security refers to the protection of a database against unauthorized or illegal access or modification. For example, a high-level password might allow

69、 a user to read from, write to, and modify the database structure, whereas a low-level password history of the modifications to a database-can be used to identify where and when a database was tampered with and it can al

70、so be used to restore the file to its original condition.</p><p>　　三、Choosing between Oracle and SQL Server</p><p>　　I have to decide between using the Oracle database and WebDB vs. Microsoft SQ

71、L Server with Visual Studio. This choice will guide our future Web projects. What are the strong points of each of these combinations and what are the negatives?</p><p>　　Lori: Making your decision will depe

72、nd on what you already have. For instance, if you want to implement a Web-based database application and you are a Windows-only shop, SQL Server and the Visual Studio package would be fine. But the Oracle solution would

73、be better with mixed platforms.</p><p>　　There are other things to consider, such as what extras you get and what skills are required. WebDB is a content management and development tool that can be used by c

74、ontent creators, database administrators, and developers without any programming experience. WebDB is a browser-based tool that helps ease content creation and provides monitoring and maintenance tools. This is a good so

75、lution for organizations already using Oracle. Oracle also scales better than SQL Server, but you will need to hav</p><p>　　The SQL Sever/Visual Studio approach is more difficult to use and requires an exper

76、ienced object-oriented programmer or some extensive training. However, you do get a fistful of development tools with Visual Studio: Visual Basic, Visual C++, and Visual InterDev for only $1,619. Plus, you will have to a

77、dd the cost of the SQL Server, which will run you $1,999 for 10 clients or $3,999 for 25 clients-a less expensive solution than Oracle’s.</p><p>　　Oracle also has a package solution that starts at $6,767, de

78、pending on the platform selected. The Oracle.com suite includes not only WebDB and Oracle8i but also other tools for development such as the Oracle application server, JDeveloper, and Workplace Templates, and the suite r

79、uns on more platforms than the Microsoft solution does. This can be a good solution if you are a start-up or a small to midsize business. Buying these tools in a package is less costly than purchasing them individually.&

80、lt;/p><p>　　Much depends on your skill level, hardware resources, and budget. I hope this helps in your decision-making.</p><p>　　Brooks: I totally agree that this decision depends in large part on

81、 what infrastructure and expertise you already have. If the decision is close, you need to figure out who’s going to be doing the work and what your priorities are.</p><p>　　These two products have different

82、 approaches, and they reflect the different personalities of the two vendors. In general, Oracle products are designed for very professional development efforts by top-notch programmers and project leaders. The learning

83、period is fairly long, and the solution is pricey; but if you stick it out you will ultimately have greater scalability and greater reliability.</p><p>　　If your project has tight deadlines and you don’t hav

84、e the time and/or money to hire a team of very expensive, very experienced developers, you may find that the Oracle solution is an easy way to get yourself in trouble. There’s nothing worse than a poorly developed Oracle

85、 application.</p><p>　　What Microsoft offers is a solution that’s aimed at rapid development and low-cost implementation. The tools are cheaper, the servers you’ll run it on are cheaper, and the developers y

86、ou need will be cheaper. Choosing SQL Sever and Visual Studio is an excellent way to start fast.</p><p>　　Of course, there are trade-offs. The key problem I have with Visual Studio and SQL Server is that you

87、’ll be tied to Microsoft operating systems and Intel hardware. If the day comes when you need to support hundreds of thousands of users, you really don’t have anywhere to go other than buying hundreds of servers, which i

88、s a management nightmare.</p><p>　　If you go with the Microsoft approach, it sounds like you may not need more than Visual Interdev. If you already know that you’re going to be developing ActiveX components

89、in Visual Basic or Visual C++, that’s warning sign that maybe you should look at the Oracle solution more closely.</p><p>　　I want to emphasize that, although these platforms have their relative strengths an

90、d weaknesses, if you do it right you can build a world-class application on either one. So if you have an organizational bias toward one of the vendors, by all means go with it. If you’re starting out from scratch, you’r

91、e going to have to ask yourself whether your organization leans more toward perfectionism or pragmatism, and realize that both “isms” have their faults.</p><p><b>　　中文譯文：</b></p><p>

92、<b>　　數(shù)據(jù)庫管理</b></p><p>　　數(shù)據(jù)庫（也稱DataBase）也稱為電子數(shù)據(jù)庫，是指由計算機特別組織的用下快速查找和檢索的任意的數(shù)據(jù)或信息集合。數(shù)據(jù)庫與其它數(shù)據(jù)處理操作協(xié)同工作，其結(jié)構(gòu)要有助于數(shù)據(jù)的存儲、檢索、修改和刪除。數(shù)據(jù)庫可存儲在磁盤或磁帶、光盤或某些輔助存儲設(shè)備上。</p><p>　　一個數(shù)據(jù)庫由一個文件或文件集合組成。這些文件中的信息可

93、分解成一個個記錄，每個記錄有一個或多個域。域是數(shù)據(jù)庫存儲的基本單位，每個域 一般含有由數(shù)據(jù)庫描述的屬于實體的一個方面或一個特性的信息。用戶使用鍵盤和各種排序命令，能夠快速查找、重排、分組并在查找的許多記錄中選擇相應(yīng)的域，建立特定集上的報表。</p><p>　　數(shù)據(jù)庫記錄和文件的組織必須確保能對信息進行檢索。早期的系統(tǒng)是順序組織的（如:字母順序、數(shù)字順序或時間順序）；直接訪問存儲設(shè)備的研制成功使得通過索引隨機訪問

94、數(shù)據(jù)成為可能。用戶檢索數(shù)據(jù)庫信息的主要方法是query（查詢）。通常情況下，用戶提供一個字符串，計算機在數(shù)據(jù)庫中尋找相應(yīng)的字符序列，并且給出字符串在何處出現(xiàn)。比如，用戶必須能在任意給定時間快速處理內(nèi)部數(shù)據(jù)。而且，大型企業(yè)和其它組織傾向于建立許多獨立的文件，其中包含相互關(guān)聯(lián)的甚至重疊的數(shù)據(jù)，這些數(shù)據(jù)、處理活動經(jīng)常需要和其它文件的數(shù)據(jù)相連。為滿足這些要求，開發(fā)郵各種不同類型的數(shù)據(jù)庫管理系統(tǒng)，如：非結(jié)構(gòu)化的數(shù)據(jù)庫、層次型數(shù)據(jù)庫、網(wǎng)絡(luò)型數(shù)據(jù)庫、

95、關(guān)系型數(shù)據(jù)庫、面向?qū)ο笮蛿?shù)據(jù)庫。</p><p>　　在非結(jié)構(gòu)化的數(shù)據(jù)庫中，按照實體的一個簡單列表組織記錄；很多個人計算機的簡易數(shù)據(jù)庫是非結(jié)構(gòu)的。層次型數(shù)據(jù)庫按樹型組織記錄，每一層的記錄分解成更小的屬性集。層次型數(shù)據(jù)庫在不同層的記錄集之間提供一個單一鏈接。與此不同，網(wǎng)絡(luò)型數(shù)據(jù)庫在不同記錄集之間提供多個鏈接，這是通過設(shè)置指向其它記錄集的鏈或指針來實現(xiàn)的。網(wǎng)絡(luò)型數(shù)據(jù)庫的速度及多樣性使其在企業(yè)中得到廣泛應(yīng)用。當(dāng)文件或記

96、錄間的關(guān)系不能用鏈表達(dá)時，使用關(guān)系型數(shù)據(jù)庫。一個表或一個“關(guān)系”，就是一個簡單的非結(jié)構(gòu)列表。多個關(guān)系可通過數(shù)學(xué)關(guān)系提供所需信息。面向?qū)ο蟮臄?shù)據(jù)庫存儲并處理更復(fù)雜的稱為對象的數(shù)據(jù)結(jié)構(gòu)，可組織成有層次的類，其中的每個類可以繼承層次鏈中更高一級類的特性，這種數(shù)據(jù)庫結(jié)構(gòu)最靈活，最具適應(yīng)性。</p><p>　　很多數(shù)據(jù)庫包含自然語言文本信息，可由個人在家中使用。小型及稍大的數(shù)據(jù)庫在商業(yè)領(lǐng)域中占有越來越重要的地位。典型的商

97、業(yè)應(yīng)用包括航班預(yù)訂、產(chǎn)品管理、醫(yī)院的醫(yī)療記錄以及保險公司的合法記錄。最大型的數(shù)據(jù)庫通常用天政府部門、企業(yè)、大專院校等。這些數(shù)據(jù)庫存有諸如摘要、報表、成文的法規(guī)、通訊錄、報紙、雜志、百科全書、各式目錄等資料。索引數(shù)據(jù)庫包含參考書目或用于找到相關(guān)書籍、期刊及其它參考文獻(xiàn)的索引。目前有上萬種可公開訪問的數(shù)據(jù)庫，內(nèi)容包羅萬象，從法律、醫(yī)學(xué)、工程到新聞、時事、游戲、分類廣告、指南等?？茖W(xué)家、醫(yī)生、律師、財經(jīng)分析師、股票經(jīng)紀(jì)人等專家和各類研究者越來