武汉理工大学数据库系统原理总复习题完整版含答案.doc

1、1武汉理工大学 数据库系统原理总复习题（完整版含答案）1. Questions1.1 What is the purpose of a database?ANSWER： The purpose of a database is to help people track of things.1.2 What is the most commonly used type of database?ANSWER: the most commonly used type of database is the relational database.1.7 Define the terms data an

2、d information. Explain how the two terms differ.ANSWER: Data are recorded facts and numbers. we can now define information as: Knowledge derived from data. Data presented in a meaningful context. Data processed by summing, ordering, averaging, grouping, comparing or other similar operations.1.10 Wha

3、t problem can occur when a database is processed by more than one user?ANSWER: When more than one user employs a database application, these is always the chance that one users work may interfere with others.1.12 What is the purpose of the largest databases at e-commerce companies such as A?ANSWER:

4、The largest databases are those that track customer browser behavior.（用来记录用户的浏览行为的。 ）1.13 How do the e-commerce companies use these databases? .ANSWER: E-commerce companies use Web activity databases to determine which items on a Web page are popular and successful and which are not.1.14 How do digi

5、tal dashboard and data mining applications differ from transaction processing applications?ANSWER: Digital dashboards and other reporting systems assess past and current performance. Data mining applications predict future performance.1.15 Explain why a small database is not necessarily simpler than

6、 a large one.What are the functions of application programs?ANSWER: Supposed we have 2 company which are different in sales but have similar database. Though the difference in sale, both have the same kinds of data, about the same number of tables of data, and the same level of complexity in data re

7、lationships. Only the amount of data varies from one to the other. Thus, although a database for a small business may be small, it is not necessarily simple.1.18 What is Structured Query Language (SQL), and why is it important?2ANSWER: Structured Query Language (SQL) is an internationally recognized

8、 standard language. Because it can be understood by all commercial DBMS products, in database processing and the fact that database applications typically send SQL statements to the DBMS for processing.1.19 What does DBMS stand for?ANSWER: The database management system.1.20 What are the functions o

9、f the DBMS?ANSWER: It can be used to create, process, and administer the database.1.21 Name three vendors of DBMS products.ANSWER: IBM, Microsoft, Oracle.1.22 Define the term database.ANSWER: A database is a self-describing collection of integrated tables.1.23 Why is a database considered to be self

10、-describing?ANSWER: A database is self-describing because it contains a description of itself. Thus, databases contain not only tables of user data, but also tables of data that describe that user data.1.24 What is metadata? How does this term pertain to a database?ANSWER: databases contain not only

11、 tables of user data, but also tables of data that describe that user data. Such descriptive data is called metadata because it is data about data.1.25 What advantage is there in storing metadata in tables?ANSWER: Because metadata is stored in tables, you can use SQL to query it. Thus, by learning h

12、ow to write SQL to query user tables, you will also learn how to write SQL to query metadata.1.26 List the components of a database other than user tables and metadata. Tables of user data Metadata Indexes Stored procedures Triggers Security data Backup/recovery data1.27 Is Microsoft Access a DBMS?

13、Why or why not?3ANSWER: No, Microsoft Access is not just a DBMS. Rather, it is a personal database system: a DBMS plus an application generator.Because although Microsoft Access contains a DBMS engine that creates, processes, and administers the database, it also contains form, report, and query com

14、ponents that are the Microsoft Access application generator1.37 List several consequences of a poorly designed database.ANSWER: -They may require application developers to write overly complex and contrived SQL to get wanted data.-they may be difficult to adapt to new and changing requirements.-they

15、 may fail in some other way.1.38 Explain two ways that a database can be designed from existing data.ANSWER:The first type of database design involves databases that are constructed from existing Data.A second way that databases are designed is for the development of new information systems.1.39 Wha

16、t is a data warehouse? What is a data mart?ANSWER: The data warehouse and data mart databases store data specifically organized for research and reporting purposes, and these data often are exported to other analytical tools, such as SASs Enterprise Miner, IBMs SPSS Data Modeler, or TIBCOs Spot fire

17、 Metrics. 1.40 Describe the general process of designing a database for a new information system.ANSWER: First, the team creates a data model from the requirements statements and then transforms that data model into a database design.41.41 Explain two ways that databases can be redesigned.ANSWER: In

18、 the first, a database is adapted to new or changing requirements. This process sometimes is called database migration. In the migration process, tables may be created, modified, or removed; relationships may be altered; data constraints may be changed; and so forth. The second type of database rede

19、sign involves the integration of two or more databases. This type of redesign is common when adapting or removing legacy systems. It is also common for enterprise application integration, when two or more previously separate information systems are adapted to work with each other. 1.42 What does the

20、 term database migration mean?ANSWER: The process of a database is adapted to new or changing requirements.1.43 Summarize the various ways that you might work with database technology.ANSWER: In our career, we may work with database technology as either a user or as a database administrator. As a us

21、er, you may be a knowledge worker who prepares reports, mines data, and does other types of data analysis or you may be a programmer who writes applications that process the database. Alternatively, you might be a database administrator who designs, constructs, and manages the database itself. Users

22、 are primarily concerned with constructing SQL statements to get and put the data they want. Database administrators are primarily concerned with the management of the database.1.44 What job functions does a knowledge worker perform?5ANSWER: preparing reports, mining data, and doing other types of d

23、ata analysis.1.45 What job functions does a database administrator perform?ANSWER: designing, constructing, and managing the database itself.1.47 What need drove the development of the first database technology?ANSWER: The need for data integration drove the development of the first database technol

24、ogy.1.48 What are Data Language/I and CODASYL DBTG?ANSWER: Data Language/I (DL/I) used hierarchies or trees (see Appendix G) to represent relationships.This subcommittee developed a standard data model that came to bear its namethe CODASYL DBTG model. It was an unnecessarily complicated model. This

25、data relationship used data structures called networks.1.49 Who was E. F. Codd?ANSWER: E.F.Codd was a little-known IBM engineer published a paper in the Communications of the ACM3 in which he applied the concepts of a branch of mathematics called relational algebra to the problem of “shared data ban

26、ks,” as databases were then known. The results of this work are now the relational model for databases, and all relational database DBMS products are built on this model. 1.50 What were the early objections to the relational model?1.51 Name two early relational DBMS products.ANSWER: Oracle Database,

27、 DB2.1.52 What are some of the reasons for the success of Oracle Database?ANSWER:1, it would run on just about any computer and just about any operating system.2, Oracle Database had, and continues to have, an elegant and efficient internal design.1.53 Name three early personal computer DBMS product

28、s.ANSWER: dBase, R:base, Paradox.1.55 What was the purpose of OODBMS products? State two reasons that 6OODBMS products were not successful.ANSWER: They were designed to make it easy to store the data encapsulated in OOP objects.There were two reasons for their lack of acceptance. First, using an OOD

29、BMS required that the relational data be converted from relational format to object-oriented format. By the time OODBMS emerged, billions upon billions of bytes of data were stored in relational format in organizational databases. No company was willing to undergo the expensive travail of converting

30、 those databases to be able to use the new OODBMS. Second, object-oriented databases had no substantial advantage over relational databases for most commercial database processing. As you will see in the next chapter, SQL is not object oriented. But it works, and thousands of developers have created

31、 programs that use it. Without a demonstrable advantage over relational databases, no organization was willing to take on the task of converting their data to OODBMS format. 1.56 What characteristic of HTTP was a problem for database processing applications?ANSWER: HTTP is a stateless protocol; a se

32、rver receives a request from a user, processes the request, and then forgets about the user and the request. Many database interactions are multistage. A customer views products, adds one or more to a shopping cart, views more products, adds more to the shopping cart, and eventually checks out. A st

33、ateless protocol cannot be used for such applications. 1.57 What is an open source DBMS product? Which of the five DBMS products that you named in answering Review Question 1.36 is historically an open source DBMS product?ANSWER: the MySQL DBMS.这套试卷没有 1.36 题啊。1.58 What has been the response of compa

34、nies that sell proprietary DBMS products to the open source DBMS products? Include two examples in your answer.ANSWER: One interesting outcome of the emergence of open source DBMS products is that companies that typically sell proprietary (closed source) DBMS products now offer free versions of thei

35、r products. For example, Microsoft now offers SQL Server 2008 R2 Express (www.microsoft. com/express/Database), and Oracle Corporation makes its Oracle Database 10g Express Edition available for free.1.59 What is XML? What comment did Bill Gates make regarding XML?7ANSWER: XML means Extensible Marku

36、p Language.Bill Gates said that “XML is the lingua-franca of the Internet Age.”1.60 What is the NoSQL movement? Name two applications that rely on NoSQLdatabases.ANSWER: Its the work is really on databases are often based on XML.Two applications that rely on NoSQLdatabases: Facebook and Twitter. 2.1

37、 What is a business intelligence (BI) system?ANSWER: Application refers to the collection of commercial information, the integration, analysis and the technical reports.2.2 What is an ad-hoc query?ANSWER: ad-hoc SQL queries is how SQL is used to “ask questions” about the data in the database.2.3 Wha

38、t does SQL stand for, and what is SQL?ANSWER: SQL stand for Structured Quqery Language. SQL is not a complete programming language, like Java or C#. Instead, it is called a data sublanguage, because it has only those statements needed for creating and processing database data and metadata.2.4 What d

39、oes SKU stand for? What is an SKU?SKU stand for stock-keeping unit. SKU is a unique identifier for each particular item that Cape Codd sells.2.5 Summarize how data were altered and filtered in creating the Cape Codd data extraction.ANSWER: the ORDER_ITEM table stores an extract of the items purchase

40、d in each order. There is one row in the table for each item in an order, and this item is identified by its SKU.The OrderNumber Column in ORDER_ITEM relates each row in ORDER_ITEM to the corresponding OrderNumber in the RETAIL_ORDER table. SKU identifies the actual item purchased by its stock-keepi

41、ng unit number. Further, the SKU column in ORDER_ITEM relates each row in ORDER_ITEM to its corresponding SKU in the SKU_DATA table2.6 Explain, in general terms, the relationships among the RETAIL_ORDER, 8ORDER_ITEM,and SKU_DATA tables.ANSWER: In general, RETAIL_ORDER, ORDER_ITEM, and SKU_DATA. The

42、RETAIL_ORDER table has data about each retail sales order, the ORDER_ITEM table has data about each item in an order, and the SKU_DATA table has data about each stock-keeping unit (SKU)2.7 Summarize the background of SQL.ANSWER: SQL was developed by the IBM Corporation in the late 1970s. It was endo

43、rsed as a national standard by the American National Standards Institute (ANSI) in 1986 and by the International Organization for Standardization (ISO).2.8 What is SQL-92? How does it relate to the SQL statements in this chapter?ANSWER: Subsequent versions of SQL were adopted in 1989 and 1992. The 1

44、992 version is sometimes referred to as SQL-92, or sometimes as ANSI-92 SQL.2.9 What features have been added to SQL in versions subsequent to the SQL-92?ANSWER: All the new versions of SQL support for Extensible Markup Language (XML) and there are many other common language features.2.10 Why is SQL

45、 described as a data sublanguage?ANSWER: Because it has only those statements needed for creating and processing database data and metadata. You can use SQL statements in many different ways. You can submit them directly to the DBMS for processing. You can embed SQL statements into client/server app

46、lication programs. You can embed them into Web pages, and you can use them in reporting and data extraction programs. You also can execute SQL statements directly from Visual Studio.NET and other development tools. 2.11 What does DML stand for? What are DML statements?ANSWER: DML stand for Data Mani

47、pulation Language, which is a category of SQL. Data manipulation language (DML) statements, which are used for querying, inserting, modifying, and deleting data.2.12 What does DDL stand for? What are DDL statements?ANSWER: DDL stand for Data definition language, which is a category of SQL. Data defi

48、nition language (DDL) statements, which are used for creating tables, relationships, and other structures 2.13 What is the SQL SELECT/FROM/WHERE framework?9ANSWER: The basic form of SQL queries uses the SQL SELECT/FROM/WHERE framework. In this framework: The SQL SELECT clause specifies which columns

49、 are to be listed in the query results. The SQL FROM clause specifies which tables are to be used in the query. The SQL WHERE clause specifies which rows are to be listed in the query results. 2.14 Explain how Microsoft Access uses SQL.ANSWER: Every time you process a form, create a report, or run a query Microsoft Access generates SQL and sends that SQL to Microsoft Access internal ADE DBMS engine. To do more than elementary database processing, you need to uncover the SQL hidden by Microsoft Access. Further, once you know SQL, you will