Question 1

An advantage of a centralized database is that there is no need for a distributed directory since all of the data is in one place.

Accepted Answer

A) True 
 B)False

Question 2

In the commit phase of the two-phase commit process, either the process is aborted or each site writes the update from their log to their database.

Accepted Answer

A) True 
 B)False

Question 3

Distributed data with no replication provides a high degree of availability.

Accepted Answer

A) True 
 B)False

Question 4

All of the following are true about a two-tiered client/server LAN, except ____.

Accepted Answer

A)  a gateway computer can link the LAN to other LANs or to the Internet 
B)  data can reside on a client PC's hard drive or at the server 
C)  searching for data is location transparent 
D)  a printer on the LAN is available to all of the client PCs 
E)  data transparency can extend to a mainframe external to the LAN 
A)  a gateway computer can link the LAN to other LANs or to the Internet 
B)  data can reside on a client PC's hard drive or at the server 
C)  searching for data is location transparent 
D)  a printer on the LAN is available to all of the client PCs 
E)  data transparency can extend to a mainframe external to the LAN

Question 5

One of the principles of data replication in a distributed database is to maximize the number of copies of any one table to control the security and concurrency issues.

Accepted Answer

A) True 
 B)False

Question 6

If the nature of the data and of the applications that use it can tolerate retrieved data not necessarily being up-to-the-minute accurate, then several "synchronous" approaches to updating replicated data are appropriate.

Accepted Answer

A) True 
 B)False

Question 7

If all went well during the prepare phase of the two-phase commit, then during the commit phase ____.

Accepted Answer

A)  only the site issuing the update request writes the update to its database 
B)  all of the involved sites write the update to their logs 
C)  all of the involved sites write the update to their databases 
D)  all of the sites except the site issuing the update request write the update to their logs 
E)  all of the sites except the site issuing the update request write the update to their databases 
A)  only the site issuing the update request writes the update to its database 
B)  all of the involved sites write the update to their logs 
C)  all of the involved sites write the update to their databases 
D)  all of the sites except the site issuing the update request write the update to their logs 
E)  all of the sites except the site issuing the update request write the update to their databases

Question 8

The more volatile the data in the database is, the more attractive is the two-phase commit type of synchronous procedure for updating replicated tables in the distributed database.

Accepted Answer

A) True 
 B)False

Question 9

If a distributed database network with data replication has one node that has a copy of every table in the database ____.

Accepted Answer

A)  the problem of data concurrency is eliminated 
B)  the issue of one site becoming a bottleneck is eliminated 
C)  the problem of data security is eliminated 
D)  at least one other copy of each table must also be stored elsewhere on the network 
E)  the problem of distributed joins is eliminated 
A)  the problem of data concurrency is eliminated 
B)  the issue of one site becoming a bottleneck is eliminated 
C)  the problem of data security is eliminated 
D)  at least one other copy of each table must also be stored elsewhere on the network 
E)  the problem of distributed joins is eliminated

Question 10

In the two-tier approach to client/server database, location transparency means that the person issuing a query at a client does not have to know whether the data is at the client or at the server.

Accepted Answer

A) True 
 B)False

Question 11

A distributed join is required when the tables needed for a join query do not all reside at any one site on the distributed network.

Accepted Answer

A) True 
 B)False

Question 12

One use of the term three-tier approach to client/server database is that data sought from one of the client PCs can be on the client's hard drive, at the LAN server, or at a mainframe beyond the LAN.

Accepted Answer

A) True 
 B)False

Question 13

If in a distributed database network, a copy of the entire database is kept at the headquarters site and each table is replicated exactly once at any one of the other sites, there is no reason for the headquarters site to ever become a bottleneck.

Accepted Answer

A) True 
 B)False

Question 14

Consider the following relational database for the Central Zoo. Central Zoo wants to maintain information about its animals, the enclosures in which they live, and its zookeepers and the services they perform for the animals. In addition, Central Zoo has a program by which people can be sponsor of animals. Central Zoo wants to track its sponsors, their dependents, and associated data.
Each animal has a unique animal number and each enclosure has a unique enclosure number. An animal can live in only one enclosure. An enclosure can have several animals in it or it can be currently empty. A zookeeper has a unique employee number. Every animal has been cared for by at least one and generally many zookeepers; each zookeeper has cared for at least one and generally many animals. Each time a zookeeper performs a specific, significant service for an animal the service type, date, and time are recorded. A zookeeper may perform a particular service on a particular animal more than once on a given day.
A sponsor, who has a unique sponsor number and a unique social security number, sponsors at least one and possibly several animals. An animal may have several sponsors or none. For each animal that a particular sponsor sponsors, the zoo wants to track the annual sponsorship contribution and renewal date. In addition, Central Zoo wants to keep track of each sponsor's dependents. A sponsor may have several dependents or none. A dependent is associated with exactly one sponsor.
News flash!!! Central Zoo now has branches in four cities: Miami (also the Zoo's headquarters), Tucson, Detroit, and Cleveland. The database structure remains the same except that the Location attribute of the ENCLOSURE relation now indicates in which of the four cities the enclosure is located.
Central Zoo has decided to reconfigure its database as a distributed database among its four locations. Distributed and replicated among these four locations, the tables have the following characteristics:
ENCLOSURE consists of 4,000 records and is used most heavily in the cities in which the individual enclosures are located.
ANIMAL consists of 50,000 records. The entire table is used in the Miami headquarters, in addition to which the records concerning individual animals are used frequently in the locations at which the animals are housed.
ZOOKEEPER consists of 1,500 records with a situation similar to the ANIMAL table.
CARES FOR consists of consists of 5,000 records with a situation similar to the ANIMAL table.
SPONSOR consists of 10,000 records and is used mostly at the Miami headquarters.
CONTRIBUTION consists of 30,000 records with a situation similar to the SPONSOR table.
DEPENDENT consists of 90,000 records with a situation similar to the SPONSOR table.
Design a distributed relational database for Central Zoo. Justify your placement, replication, and partitioning of the tables.
 $$\begin{array} { | l | l | l | l | l |} 
\hline\text { Enclosure } & & & & \text { Date } \
\text { Number } & \text { Type } & \text { Location } & \text { Size } & \text { Built } \
\hline
\end{array}$$ ENCLOSURE Relation
 $\begin{array}{|l|l|l|l|l|l|l|}
\hline \text { Animal } & & \text { Animal } & & \text { Country } & & \text { Enclosure } \
\text { Number } & \text { Species } & \text { Name } & \text { Gender } & \text { Of Birth } & \text { Weight } & \text { Number } \
\hline
\end{array}$ ANIMAL Relation
 $$\begin{array} { | l | l | l | l | } 
\hline \text { Employee } & \text { Employee } & & \text { Year } \
\text { Number } & \text { Narne } & \text { Title } & \text { Hired } \
\hline
\end{array}$$ ZOOKEEPER Relation
 $$\begin{array} { | l | l | l | l | l |} 
\hline\text { Animal } & \text { Employee } & \text { Service } & & \
\text { Number } & \text { Number } & \text { Type } & \text { Date } & \text { Time } \
\hline
\end{array}$$ CARES FOR Relation
 $$\begin{array} { | l | l | l | l | l |} 
\hline \text { Sponsor } & \text { Social Security } & \text { Sponsor } & & \
\text { Number } & \text { Number } & \text { Name } & \text { Address } & \text { Telephone }\
\hline
\end{array}$$ SPONSOR Relation
 $$\begin{array} { | l | l | l | l | } 
\hline \text { Animal } & \text { Sponsor } & \text { Annual } & \text { Renewal } \
\text { Number } & \text { Number } & \text { Contribution } & \text { Date } \
\hline
\end{array}$$ CONTRIBUTION Relation
 $$\begin{array} { | l | l | l | l | } 
\hline \text { Sponsor } & \text { Dependent } & & \text { Date of } \
\text { Number } & \text { Name } & \text { Relationship } & \text { Birth } \
\hline
\end{array}$$ DEPENDENT Relation

Accepted Answer

Since the ENCLOSURE records are "used mo

Question 15

During the prepare phase of the two-phase commit____.

Accepted Answer

A)  only the site issuing the update request writes the update to its database 
B)  all of the involved sites write the update to their logs 
C)  all of the involved sites write the update to their databases 
D)  all of the sites except the site issuing the update request write the update to their logs 
E)  all of the sites except the site issuing the update request write the update to their databases 
A)  only the site issuing the update request writes the update to its database 
B)  all of the involved sites write the update to their logs 
C)  all of the involved sites write the update to their databases 
D)  all of the sites except the site issuing the update request write the update to their logs 
E)  all of the sites except the site issuing the update request write the update to their databases

Question 16

A distributed database management system manages the distributed data as a single, logical database.

Accepted Answer

A) True 
 B)False

Question 17

Consider a distributed relational database in which there is no data replication. All of the following are true, except ____.

Accepted Answer

A)  all of the table on the network is still available even if one site that has some tables goes down 
B)  every table can be placed at the site at which it is most heavily used 
C)  if one site goes down then the data at that site cannot be accessed there or anywhere else on the network 
D)  the integration of two tables that are not located at the same site will require a distributed join 
E)  if one site goes down at least some of the database's tables will still be accessible 
A)  all of the table on the network is still available even if one site that has some tables goes down 
B)  every table can be placed at the site at which it is most heavily used 
C)  if one site goes down then the data at that site cannot be accessed there or anywhere else on the network 
D)  the integration of two tables that are not located at the same site will require a distributed join 
E)  if one site goes down at least some of the database's tables will still be accessible

Question 18

Placing a complete copy of the database at every site on the distributed network maximizes availability and minimizes concurrent update problems.

Accepted Answer

A) True 
 B)False

Question 19

The two-phase commit process is used for asynchronous updating of replicated data.

Accepted Answer

A) True 
 B)False

Question 20

Dispersing tables on a distributed network without replication avoids the need for a distributed directory.

Accepted Answer

A) True 
 B)False

An advantage of a centralized database is that there is no need for a distributed directory since all of the data is in one place.

In the commit phase of the two-phase commit process, either the process is aborted or each site writes the update from their log to their database.

Distributed data with no replication provides a high degree of availability.

All of the following are true about a two-tiered client/server LAN, except ____.

One of the principles of data replication in a distributed database is to maximize the number of copies of any one table to control the security and concurrency issues.

If the nature of the data and of the applications that use it can tolerate retrieved data not necessarily being up-to-the-minute accurate, then several "synchronous" approaches to updating replicated data are appropriate.

If all went well during the prepare phase of the two-phase commit, then during the commit phase ____.

The more volatile the data in the database is, the more attractive is the two-phase commit type of synchronous procedure for updating replicated tables in the distributed database.

If a distributed database network with data replication has one node that has a copy of every table in the database ____.

In the two-tier approach to client/server database, location transparency means that the person issuing a query at a client does not have to know whether the data is at the client or at the server.

A distributed join is required when the tables needed for a join query do not all reside at any one site on the distributed network.

One use of the term three-tier approach to client/server database is that data sought from one of the client PCs can be on the client's hard drive, at the LAN server, or at a mainframe beyond the LAN.

If in a distributed database network, a copy of the entire database is kept at the headquarters site and each table is replicated exactly once at any one of the other sites, there is no reason for the headquarters site to ever become a bottleneck.

During the prepare phase of the two-phase commit____.

A distributed database management system manages the distributed data as a single, logical database.

Consider a distributed relational database in which there is no data replication. All of the following are true, except ____.

Placing a complete copy of the database at every site on the distributed network maximizes availability and minimizes concurrent update problems.

The two-phase commit process is used for asynchronous updating of replicated data.

Dispersing tables on a distributed network without replication avoids the need for a distributed directory.

Data: the New Corporate Resource

Data Modeling

The Database Management System Concept

Relational Data Retrieval: SQL

The Relational Database Model: Introduction

The Relational Database Model: Additional Concepts

Logical Database Design

Physical Database Design

Object-Oriented Database Management

Data Administration, Database Administration, and Data Dictionaries

Database Control Issues: Security, Backup and Recovery, Concurrency

The Data Warehouse

Database and the Internet

Filters

Exam 12: Clientserver Database and Distributed Database

An advantage of a centralized database is that there is no need for a distributed directory since all of the data is in one place.

In the commit phase of the two-phase commit process, either the process is aborted or each site writes the update from their log to their database.

Distributed data with no replication provides a high degree of availability.

All of the following are true about a two-tiered client/server LAN, except ____.

One of the principles of data replication in a distributed database is to maximize the number of copies of any one table to control the security and concurrency issues.

If the nature of the data and of the applications that use it can tolerate retrieved data not necessarily being up-to-the-minute accurate, then several "synchronous" approaches to updating replicated data are appropriate.

If all went well during the prepare phase of the two-phase commit, then during the commit phase ____.

The more volatile the data in the database is, the more attractive is the two-phase commit type of synchronous procedure for updating replicated tables in the distributed database.

If a distributed database network with data replication has one node that has a copy of every table in the database ____.

In the two-tier approach to client/server database, location transparency means that the person issuing a query at a client does not have to know whether the data is at the client or at the server.

A distributed join is required when the tables needed for a join query do not all reside at any one site on the distributed network.

One use of the term three-tier approach to client/server database is that data sought from one of the client PCs can be on the client's hard drive, at the LAN server, or at a mainframe beyond the LAN.

If in a distributed database network, a copy of the entire database is kept at the headquarters site and each table is replicated exactly once at any one of the other sites, there is no reason for the headquarters site to ever become a bottleneck.

During the prepare phase of the two-phase commit____.

A distributed database management system manages the distributed data as a single, logical database.

Consider a distributed relational database in which there is no data replication. All of the following are true, except ____.

Placing a complete copy of the database at every site on the distributed network maximizes availability and minimizes concurrent update problems.

The two-phase commit process is used for asynchronous updating of replicated data.

Dispersing tables on a distributed network without replication avoids the need for a distributed directory.

Data: the New Corporate Resource

Data Modeling

The Database Management System Concept

Relational Data Retrieval: SQL

The Relational Database Model: Introduction

The Relational Database Model: Additional Concepts

Logical Database Design

Physical Database Design

Object-Oriented Database Management

Data Administration, Database Administration, and Data Dictionaries

Database Control Issues: Security, Backup and Recovery, Concurrency

The Data Warehouse

Database and the Internet

Filters