Question 1

Clients and servers can exist on platforms with different hardware and operating systems,but they must use the same DBMSs and programming languages to be interoperable.

Accepted Answer

Clients and servers can communicate through standard communication protocols and interfaces, such as HTTP or TCP/IP, which do not require them to use the same hardware or operating system. The use of the same DBMSs and programming languages can facilitate interoperability, but it is not a strict requirement. Different DBMSs can also communicate through standard interfaces such as SQL or ODBC, and programming languages can communicate through APIs or web services.

Question 2

In client-server database development,proprietary methods typically allow for easier resolution of problems because one vendor is responsible,but these methods may prove to be expensive and inflexible in the long run.

Accepted Answer

Proprietary methods in client-server database development may provide easier problem resolution since one vendor is responsible, but they can become expensive and inflexible in the long run.

Question 3

Message-oriented middleware provides built-in intelligence but use simple messages.In contrast,transaction-processing monitors provide much less built-in intelligence but support more complex messages.

Accepted Answer

Message-oriented middleware (MOM) typically handles simple, asynchronous messages without built-in intelligence, focusing on communication between distributed systems. Transaction-processing monitors, however, offer built-in intelligence to manage complex transactions, ensuring data integrity and consistency across multiple operations.

Question 4

Some of the disadvantages of distributed data are increased data duplication,a higher complexity of database design,and a higher complexity of providing security for data distributed among multiple sites.

Accepted Answer

The statement is true. Distributed data can lead to increased data duplication, a more complex database design, and more complex security measures to ensure data is protected across multiple sites.

Question 5

The Web Services Architecture uses the HTTP,FTP,and TCP-IP protocols for sending and receiving XML messages.

Accepted Answer

The Web Services Architecture uses the HTTP, SOAP, and TCP-IP protocols for sending and receiving XML messages.

Question 6

In a two-tier client-server architecture,the PC client contains the user interface code,the server contains the data access logic,and the client and server share the validation and business logic.

Accepted Answer

In a two-tier client-server architecture, the client is responsible for the user interface and the server is responsible for the data access logic. However, both the client and server may share the validation and business logic.

Question 7

Intranets differ from the Internet in that they do not use TCP or IP protocols to communicate.

Accepted Answer

Intranets use the same TCP/IP protocols as the Internet to communicate, but they are private networks that are restricted to a specific organization or group of users. The main difference between the two is that the Intranet is accessible only within the organization, while the Internet is accessible from anywhere in the world.

Question 8

To extend its existing non-distributed DBMS to a tightly-integrated distributed DBMS,a business needs only to buy an extra component from a third-party vendor or the DBMS vendor.

Accepted Answer

To convert an existing non-distributed DBMS to a distributed DBMS, it requires significant modifications to the current system's architecture, including adding network interfaces, changing data sharing protocols, and ensuring consistency across multiple sites. Therefore, simply adding an extra component may not be enough, and significant effort from the business and DBMS vendor is usually required.

Question 9

Flexibility,scalability,and simplicity are all advantages of distributed processing.

Accepted Answer

The answer of Flexibility,scalability,and simplicity are all advantages of distributed...

Question 10

Vertical fragments can be defined using projection operations.

Accepted Answer

Vertical fragments are created by projecting a subset of attributes from a relation. Therefore, projection operations are used to define vertical fragments.

Question 11

Distributed DBMSs must conform to the Three Schema Architecture just like traditional DBMSs do.

Accepted Answer

Distributed DBMSs do not necessarily have to conform to the Three Schema Architecture, which is a framework for traditional DBMSs to ensure the database's physical schema is separated from the application programs. Distributed DBMSs focus on the distribution of data across multiple sites, and while they may use aspects of the Three Schema Architecture, it is not a requirement.

Question 12

PC clients in a two-tier architecture are sometimes called "thin clients" because of the large amount of business logic they contain.

Accepted Answer

In a two-tier architecture, PC clients are often referred to as "fat clients" or "thick clients" because they contain a significant amount of business logic, as opposed to "thin clients" which rely on the server for most of the business logic.

Question 13

XML is a meta language that supports the specification of other languages.

Accepted Answer

XML is known as a meta language because it provides a way to define other languages and data formats. It is commonly used for exchanging data between different computer systems and applications.

Question 14

Scalability refers to the ability to add and remove capacity in small units.Horizontal scalability refers to the ability to add capacity on the server side.Vertical scalability refers to the ability to add capacity on the client side through additional workstations and movement of work between clients and servers.

Accepted Answer

Scalability indeed refers to the ability to add and remove capacity in small units. However, horizontal scalability means adding more machines or instances to a pool of resources to handle increased load, while vertical scalability means adding more power (CPU, RAM) to an existing machine. The explanation about vertical scalability referring to the client side is incorrect; it pertains to increasing the capacity of a single server.

Question 15

Scalability refers to the ease of maintaining and adapting a system.

Accepted Answer

Scalability refers to the ability of a system to handle a growing amount of work or its potential to accommodate growth, not specifically to maintenance or adaptation.

Question 16

In multiple-tier client-server database architecture,software maintenance is difficult,it is complex to implement,and it relies mostly on proprietary software rather than open standards.

Accepted Answer

Multiple-tier client-server database architecture, while complex to implement, does not necessarily rely mostly on proprietary software. It can be built using open standards and technologies, and its modular nature can actually facilitate maintenance by isolating changes to specific layers.

Question 17

Horizontal fragments can be defined using restriction or outer-join operations.

Accepted Answer

Horizontal fragmentation is defined using selection or restriction operations based on rows, not outer-join operations which are used to combine rows from two or more tables.

Question 18

In a tightly integrated distributed DBMS,the fragmentation schema contains the definition of each fragment and the allocation schema contains the location of each fragment.

Accepted Answer

This is true. In a tightly integrated distributed DBMS, the fragmentation schema defines how data is divided into fragments and the allocation schema specifies where each fragment is located. The aim is to create a distributed database that optimizes performance and minimizes the amount of data that needs to be transmitted over the network.

Question 19

Fragmentation transparency requires the least effort from the user to write SQL commands for a specific task,but requires the most work for the DBMS.

Accepted Answer

Fragmentation transparency means that the user does not have to be aware of the physical distribution of data across multiple servers in a distributed database system. This requires more work from the DBMS to manage the distribution and consistency of data across servers, but it reduces the complexity for the user in terms of writing SQL commands. Therefore, the statement is true.

Question 20

Middleware is a software component in a client-server architecture that performs process management.

Accepted Answer

Middleware acts as a bridge between client and server, and manages processes such as authentication, message routing, data transformation, and more.

Quiz 17: Client-Server Processing and Distributed Databases