Deck 17: Client-Server Processing and Distributed Databases

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.

Answer 1

False

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.

Answer 2

True

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.

Answer 3

False
Explanation: Transaction-processing monitors provide built-in intelligence but use simple messages. In contrast, message-oriented middleware provides much less built-in intelligence but supports more complex messages.

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.

Question 5

The Web Services Architecture uses the HTTP,FTP,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.

Question 7

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

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.

Question 9

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

Question 10

Vertical fragments can be defined using projection operations.

Question 11

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

Question 12

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

Question 13

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

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.

Question 15

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

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.

Question 17

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

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.

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.

Question 20

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

Question 21

When the primary copy protocol is used for replicated data,secondary copies are updated at the same time as the primary copy to keep the database consistent.

Question 22

Which of the following is one of the types of client server architectures discussed?

A) two-tier architecture
B) three-tier architecture
C) web services architecture
D) hyper object broker architecture

Question 23

The server-side approach has the following feature:

A) The web server may be connected to the database server via a middleware server with listener
B) The web server may be augmented with middleware and directly connects to the database server
C) There is no need for external program
D) All of the above

Question 24

Which of the following is not a kind of middleware?

A) transaction-processing monitors
B) message-oriented middleware
C) object-request brokers
D) Meta data repository hyper-access utilities Data access middleware would be another type of middleware

Question 25

With location transparency,a SELECT query must use the intersection operator to collect the rows from the various fragments.

Question 26

In a client-server database architecture which of the following is not a middleware function?

A) Validation of data
B) Insuring interoperability among clients and servers
C) Scheduling messages arriving to a server
D) Routing messages

Question 27

An overriding design issue in client-server database architecture is:

A) Number of clients
B) Number of servers
C) Division of processing
D) Choice of hardware for client

Question 28

In distributed transaction processing,transactions do not necessarily have to conform to all of the ACID properties that non-distributed transactions do.

Question 29

In a three-tier client-server database architecture,the "third tier" is:

A) The database
B) A middleware server
C) An application server
D) Either a middleware server or an application server

Question 30

Which of the following is an advantage of Parallel database processing?

A) speedup
B) availability
C) scalability for predictive performance improvements
D) all of the above

Question 31

Which of the following is not a typical example of flexibility provided by a client-server approach with distributed processing?

A) Easily change the database language
B) Change the user interface for the sales department
C) Supports reusability through object orientation
D) Make a user interface for the newly created position of human resources advisor

Question 32

The following features permitted distributed processing in the 1980s:

A) Support for high-speed data transfer by local area networks
B) Support for graphical interfaces by personal computers
C) File sharing
D) All of the above

Question 33

In parallel database processing one of the standard classifications of architecture is referred to as shared everything (SE).Which of the statements below is true of the SE architecture?

A) In the SE architecture, each processor has its private memory, but disks are shared among all processors.
B) In the SE architecture, each processor has its own memory and disks.
C) In the SE approach, memory and disks are shared among a collection of processors.
D) None of the above

Question 34

In a three-tier client-server database architecture,the application server typically will contain:

A) Specialized software such as report writing
B) Business logic
C) Transaction processing software
D) Data validation

Question 35

In a parallel database architecture with clustering,which of the following statements is true about the clustered nothing (CN)architecture?

A) In the CN architecture, the processors in each cluster share all disks, but nothing is shared across clusters.
B) In the CN architecture, the processors in each cluster share no resources, but each cluster can be manipulated to work in parallel to perform a task.
C) Clustering has no impact on resource sharing or processing of tasks
D) All of the above

Question 36

Which of the following is not a goal of distributed data?

A) Decreased communication costs
B) Increased corporate control over data
C) Increased data availability
D) Increased performance

Question 37

Distributed query processing involves both local and global optimization,so there are more access plans to choose from in distributed query processing than in centralized query processing.

Question 38

Which of the following is a design issue that affects the design of a client-server database?

A) division of processing
B) distribution of storage of data
C) process management
D) A and C

Question 39

One of the tasks that must be performed by all client-server architectures is workflow.Which statement below best describes this task?

A) code to ensure the consistency of the database and user inputs.
B) code to perform business functions such as payroll calculations, eligibility requirements, and interest calculations.
C) code to ensure completion of business processes
D) code to maintain the graphical user interface.

Question 40

The two-phase commit protocol involves a voting phase and a decision phase which must be coordinated by a centralized coordinator site.

Question 41

In a client-server architecture,____________code is code to ensure the consistency of the database and user inputs.

Question 42

_______________________ can be used to provide a uniform interface between relational and non-relational data using SQL.

Question 43

In a(n)____________________ architecture,performance is improved by the addition of either a middleware server or an application server.

Question 44

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

Question 45

When a distributed DBMS is tightly integrated,which of the following statements is not true?

A) The distributed data manager may access the internal state of local data managers
B) The distributed DBMS may include legacy databases
C) The distributed data manager efficiently supports distributed queries
D) The distributed data manager efficiently supports distributed transactions

Question 46

The primary design issues that influence the performance of the parallel database architectures include which of the following?

A) load balancing
B) cache coherence
C) interprocessor communication
D) all of the above

Question 47

Which of the following statement is not true of loosely integrated DBMS?

A) All local DBMS must be relational
B) Some local DBMS may be hierarchical
C) A local mapping schema provides information to use local data in the distributed database
D) A local mapping schema may provide information to use data of a non-standard data type

Question 48

Which of the following statements is true about parallel and distributed databases with respect to autonomy?

A) Parallel databases provide site autonomy while distributed databases do not.
B) Distributed databases provide site autonomy while parallel databases do not.
C) There is no difference between parallel databases and distributed databases with respect to autonomy.
D) Autonomy of the database is dependent on the DBMS vendor not its architecture.

Question 49

In a(n)____________________ architecture,division of processing problems are addressed by the addition of a middleware server and one or more application servers.

Question 50

The interoperability among clients and servers and the efficient processing of messages between them is referred to in a client-server architecture as ___________________.

Question 51

The allocation of tasks between clients and servers is known as __________________.

Question 52

Which of the following is true of a fragment in a distributed DBMS?

A) It may contain specific rows of a table
B) It may contain specific columns of a given table
C) It may be replicated at several sites
D) All of the above

Question 53

In a(n)_____________________ architecture,a PC client and a database server interact directly to request and transfer data.

Question 54

Which of the following statements is not true about distributed concurrency control?

A) It is simpler when coordination is centralized rather than distributed
B) It has the same type of problems with replicated data when coordination is centralized or is distributed
C) It is more reliable when coordination is centralized rather than distributed
D) It is more complex than centralized concurrency control

Question 55

The design and allocation of fragments require data about:

A) Frequencies of queries
B) Frequencies of parameter values
C) Frequencies of originating sites for each query
D) All of the above

Question 56

In a distributed DBMS,the distributed data manager:

A) Optimizes global query execution
B) Coordinates global concurrency control
C) Coordinates recovery from failures across all sites
D) All of the above

Question 57

A SQL query with local format transparency needs to specify:

A) Fragments
B) Locations
C) Fragments and locations
D) Local formats

Question 58

In a distributed DBMS:

A) A query or a transaction is able to access/process data stored at several sites
B) A query may only access one local database
C) A transaction may only update one local database
D) A query or transaction may only be issued at the site of the local database it will access

Question 59

Which one of the following is not true about distributed query processing?

A) Minimizing resources allows for minimizing response time
B) For wide area networks, communication costs are often the dominant cost
C) For local area networks, communication costs are often comparable to local costs
D) Distributed query processing is much more complex than centralized query processing

Question 60

A(n)_______________________,the oldest kind of middleware,relieves the operating system of managing database processes.

Question 61

___________________ is a concurrency control protocol for distributed transactions in which write locks are necessary only for the replicated fragment that has been designated as the primary copy.

Question 62

_________ code is code to ensure completion of business processes.____________ code may route forms,send messages about a deadline,and notify users when a business process is completed.

Question 63

_______________ provide a high level of interoperability and message intelligence.They also resolve platform differences between a client and a server.

Question 64

A level of data independence in distributed DBMSs in which queries can be formulated without knowing the locations or local formats of the fragments is _______________________.

Question 65

In a loosely integrated distributed DBMS environment,a(n)___________________ describes the exportable data at the site and provides conversion rules to translate data from a local format into a global format.

Question 66

A relational algebra operator that is useful for distributed database processing,in which only the rows of the first table appear in the result,is a(n)________________.

Question 67

A level of data independence in distributed DBMSs in which queries must specify the fragments and their locations,but not their local format,is known as _____________________.

Question 68

The ______________optimizes query execution across sites,coordinates concurrency control and recovery across sites,and controls access to remote data.

Question 69

In a distributed database environment,a(n)___________________ can be a query that combines data from more than one site or a transaction that updates data at more than one site.

Question 70

In the Web Services Architecture,the WSFL,UDDI,WSDL,and SOAP standards are ________ compliant languages.

Question 71

____________ is an architecture that supports electronic commerce among organizations.A set of related Internet standards supports high interoperability among service requestors,service providers,and service registries.

Question 72

In a distributed DBMS environment,the ______________________ optimizes query execution across sites,coordinates concurrency control and recovery across sites,and controls access to remote data.

Question 73

_____________________ is the highest level of data independence in distributed DBMSs,and is so transparent that users perceive the distributed database as a centralized database.

Question 74

A ________ DBMS is a DBMS capable of utilizing tightly-coupled computing resources (processors,disks,and memory).Tight coupling is achieved by networks with data exchange time comparable to the time of the data exchange with a disk.

Question 75

A ___________ is a tight coupling of two or more computers so that they behave as a single computer.

Question 76

A protocol used for distributed commit processing in which the coordinator site and participant sites act in unison to decide to commit or abort their sub-transactions is known as the _________________.