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Instructor's Manual, Chapter 2
Management Information Systems, Second Canadian Edition
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Chapter 7
Managing Data Resources
Teaching Objectives
Students should be able to answer the following questions:
1. Why do businesses have trouble finding the information they need in their information
systems?
2. How does a database management system help businesses improve the organization of
their information?
3. How do the principal types of database models affect the way businesses can access and
use information?
4. What are the managerial and organizational requirements of a database environment?
5. What new tools and technologies can make databases more accessible and useful?
Key Terms
The following alphabetical list identifies the key terms discussed in this chapter. The page
number for each key term is provided.
Application server, 249
Attribute, 231
Data administration, 243
Data definition language, 234
Data dictionary, 234
Data element, 234
Data manipulation language, 234
Data mart, 246
Data redundancy, 232
Data warehouse, 245
Database, 231
Database (rigorous definition), 233
Database administration, 244
Database management system (DBMS), 233
Database server, 248
Datamining, 247
Distributed database, 243
Entity, 231
Entity-relationship diagram, 241
Field, 231
File, 231
Hierarchical DBMS, 237
Hypermedia database, 248
Information policy, 244
Key field, 231
Legacy system, 237
Logical view, 234
Normalization, 242
Object-oriented DBMS, 239
Object-relational DBMS, 239
Online analytical processing (OLAP), 245
Physical view, 234
Program-data dependence, 232
Record, 231
Relational DBMS, 235
Structured Query Language (SQL), 234
Tuple, 235
Teaching Suggestions
The essential message of this chapter is the statement that “Organizations need to manage
their data assets very carefully to make sure that the data are easily accessed and used by
managers and employees across the organization.” Data have now become central and even
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vital to organizations. You can illustrate these comments by referencing the opening vignette,
“Singapore's Tourism Board Learns to Manage Its Data.” The opening vignette shows how the
Singapore Tourism Board (STB) had problems collecting, storing, and analyzing visitor data.
The STB created a data warehouse to help manage the board's data. The data warehouse has
provided the STB with numerous benefits, including efficiency, reduced time, and reduced
labour. To facilitate class discussion, ask your students to answer the following questions:
1.
2.
3.
4.
What caused the problems that the STB experienced?
What technology was used to help solve the problem?
What is a data warehouse, and how did the STB use it?
What benefits did the STB enjoy after implementing the data warehouse?
Section One reviews how data are organized in the traditional file environment. This section
introduces students to file organization terms and concepts and problems with the traditional file
environment. This section is important since it introduces terminology that is important to the
chapter and explains why organizations have had (and are still having) problems with data
management. In fact, this section's main point is to show how data management has changed
and the reason why — that data must be organized, they must be accessed easily by those who
need access, and they must be protected from the wrong people accessing, modifying, or
harming the data. This section also explains why multiple computer systems have redundantly
stored data, often resulting in confusion and data integrity problems.
Section Two, ”The Database Approach to Data Management,” introduces students to a
database management system and its three components, important database terminology,
types of databases, and the elements of SQL. If you have access to a relational DBMS during
class time, you can demonstrate several of the concepts presented in this section.
At first, many of your students may not be able to distinguish between traditional and database
systems, and they may not be able to distinguish between the various types of database
systems. Your most important task in sections 7.2 through 7.4 is to help your students
understand the values of each of the types of databases and then distinguish between them.
They will likely hear terms like “logical” and “physical” and may not understand them. Try to give
several examples to help differentiate between a logical view and a physical view.
While datamining and the Web have made database management systems more important,
students find that there is too much terminology to master. You should explain to your students
that there are several models of databases: hierarchical, network, relational, and objectoriented, and each has its own terminology.
To illustrate the different database models, you can use a simple dating program as an
example. In the problem, you will have two files — people to date and dates (or date events).
You can show the difference in how each model sets up the files from the hierarchical master
file approach through network links through relational tables.
Section Three, “Creating a Database Environment,” introduces students to database design and
management requirements for database systems. Help your students see how a conceptual
design allows them to analyze and understand the data from a business perspective while
physical design shows how the database is arranged on direct access storage devices. At this
point, you can use the enrollment process at your university as an example. Have your students
prepare a conceptual design for the enrollment process. If you have time and as a class activity,
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ask your students to prepare an entity-relationship diagram as well as to normalize the data.
Your students will need guidance from you to complete this activity, but it will help them see and
understand the logical design process.
This section also introduces students to distributed databases and the two main ways of
distributing a database. You can give your students examples and then ask the students to
discuss whether partitioning or replication would be their choice.
Section Four, “Database Trends,” focuses on newer technology, such as multidimensional
analysis, data warehouses, datamining, and hypermedia databases. Regardless of their career
choice, students need to be aware of these new, very important technologies. For example,
data warehouses and data marts are important to many people, partly because they are critical
for those who want to use datamining, which in turn has many uses in management analysis
and business decisions. Keep in mind as you teach this chapter that managing data resources
can be very technical, but many students will need and want to know the business uses
andimpacts. In the end, effectively managing data is the goal; doing it in a way that will enable
your students to contribute to the success of their organization is the reason why most students
are in this course.
“Window On” Boxes
Window on Management: A Database Shows the World Awash in Stolen Nuclear
Material
What are the advantages of using a database to track stolen or lost nuclear material?
By storing data about stolen or lost nuclear material in a central location, a more comprehensive
picture is provided. Access to this information is easier, given that you are cleared to access the
data. Approved researchers and government officials can use this database to help answer
questions that they might have. The researchers can retrieve only the information that they need
and be somewhat certain that the information is reliable. Also, it gives officials a better idea of
who has the nuclear material in question and allows for better tracking of the material. Data
stored in the database are also easier to update since the data are stored in a single repository.
Using a database also eliminates problems with data redundancy and confusion, lack of
flexibility, poor security, and lack of data sharing and availability.
How can such data be better managed using a DBMS?
A DBMS allows the data to be stored and managed in a single database and thus facilitates the
retrieval of the data. The DBMS also allows the user to query the database and retrieve the data
that she needs. For instance, the researcher may want to retrieve all related data about the
missing fuel rod that later resurfaced in Italy. The DBMS can facilitate this information retrieval.
Window on Organizations: Public Databases for Sale: Boon to Business or Threat
to Privacy
Considering these examples along with your own views on regulating the use of public
databases, argue in support of the unregulated use of these databases, and then argue in
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support of those who believe their unregulated use is a violation of an individual’s
privacy.
The situations presented in this Window on Organizations box will spark much debate among
your students. Consider organizing your class into groups consisting of four students per group.
Ask half of the groups to prepare arguments in favour of using the information in public
databases, and have the remaining groups prepare arguments for protecting the information
contained in the public databases. Once the groups have prepared their arguments, have each
group from the favorable side give five reasons why the information should be readily
accessible. Alternatively, ask each group from the privacy side of the argument to give five
reasons why the information should remain protected and private. Although there will be overlap
among the groups' answers, you should come up with some good, in-depth lists for each side.
Remind students that Chapter 5 discusses the ethical and social issues in the digital firm. The
Manager's Toolkit from Chapter 5 presents students with a five-step process for conducting an
ethical analysis. Your students should apply the ethical analysis to the situations presented in
this Window on Organizations box. Ask your students which ethical principles should be applied
to the situations presented here.
For Discussion Questions
1. It has been said that you do not need database management software to create a
database environment. Discuss this view.
A database is a collection of data organized to service many applications at the same time
by storing and managing data so that they appear to be in one location. It is not mandated
that a database have a DBMS. What is most important is the concept of a database — a
model for organizing information so that it can be stored and accessed flexibly and
efficiently. Without the right vision of a database and data model, a DBMS is not effective.
A DBMS is special software to create and maintain a database. It enables individual
business applications to extract the data they need without having to create separate files
or data definitions in their computer programs. However, the use of a DBMS can reduce
program-data dependence along with program development and maintenance costs.
Access and availability of information can be increased because users and programmers
can perform ad hoc queries of data in the database. The DBMS allows the organization to
centrally manage data, its use, and security.
2. To what extent should end users be involved in the selection of a database
management system and database design?
End users should be involved in the selection of a database management system and the
database design. Developing a database environment requires much more than just
selecting the technology. It requires a change in the corporation’s attitude toward
information. The organization must develop a data administration function and a data
planning methodology. End-user involvement can be instrumental in mitigating the political
resistance organizations may have to many key database concepts, especially to sharing
information that has been controlled exclusively by one organizational group.
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Review Questions
1. Why is file management important for overall system performance?
Information cannot be used effectively if it is stored in a disorganized, inflexible manner.
Without proper file management, it may be difficult and even impossible to extract
information from an automated system. Retrieving a simple report can be timely and costly
if the information is not properly managed. File management must also be flexible enough
to accommodate new pieces of information or to combine different pieces of information in
changing ways. When computer files are poorly managed, poor performance, high costs,
and minimal flexibility will result.
2. List and describe each of the components in the data hierarchy.
Figure 7-1 shows the data hierarchy. The data hierarchy includes bits, bytes, fields,
records, files, and databases. Data are organized in a hierarchy that starts with the bit,
which is represented by either a 0 (off) or a 1 (on). Bits can be grouped to form a byte to
represent one character, number, or symbol. Bytes can be grouped to form a field, such as
a name or date, and related fields can be grouped to form a record. Related records can
be collected to form files, and related files can be organized into a database.
3. Define and explain the significance of entities, attributes, and key fields.
An entity is a person, place, thing, or event on which information can be obtained. An
attribute is a piece of information describing a particular entity. A key field is a field in a
record that uniquely identifies instances of that unique record so that it can be retrieved,
updated, or sorted. For example, a person’s name cannot be a key because there can be
another person with the same name whereas a social insurance number is unique. Also a
product name may not be unique, but a product number can be designed to be unique.
4. List and describe some of the problems of the traditional file environment.
Problems with the traditional file environment include data redundancy and confusion,
program-data dependence, lack of flexibility, poor security, and lack of data sharing and
availability. Data redundancy is the presence of duplicate data in multiple data files. In this
situation, confusion results because the data can have different meanings in different files.
Program-data dependence is the tight relationship between data stored in files and the
specific programs required to update and maintain those files. This dependency is very
inefficient, resulting in the need to make changes in many programs when a common
piece of data, such as the postal codeformat, changes. Lack of flexibility refers to the fact
that it is very difficult to create new reports from data when needed. Ad hoc reports are
impossible to generate; a new report could require several weeks of work by more than
one programmer and the creation of intermediate files to combine data from disparate
files. Poor security results from the lack of control over the data because the data are so
widespread. Data sharing is virtually impossible because it is distributed in so many
different files around the organization.
5. Define the terms database and database management system.
A database is a collection of data organized to service many applications efficiently by
storing and managing data so that they appear to be in one location. It also minimizes
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redundant data. A database management system (DBMS) is special software that permits
an organization to centralize data, manage them efficiently, and provide access to the
stored data by application programs.
6. Name and briefly describe the three components of a DBMS.
Data definition language, data manipulation language, and data dictionary are the three
components of a database management system. The data definition language is the
formal language used by programmers to specify the content and structure of the
database. The data manipulation language is the language used to manipulate data in the
database. It contains commands that permit end users and programming specialists to
extract data from the database to satisfy information requests and develop applications.
The data dictionary is an automated or manual file that stores definitions of data elements
and data characteristics such as usage, physical representation, ownership, authorization,
and security.
7. What is the difference between logical and physical views of data?
A logical view of data is the way data are perceived by end users or business specialists.
A physical view of data is the way the data are actually organized and structured on
physical storage media.
8. List some benefits of a DBMS.
A DBMS can reduce the complexity of the information systems environment, reduce data
redundancy and inconsistency, eliminate data confusion, create program-data
independence, reduce program development and maintenance costs, enhance flexibility,
enable the ad hoc retrieval of information, improve access and availability of information,
and allow for the centralized management of data, their use, and security.
9. Describe the principal types of databases and the advantages and disadvantages of
each.
The principal types of databases discussed in the textbook include relational, hierarchical,
network, and object-oriented. The relational database model organizes data into two
dimensional tables. The relational model can relate any piece of information in one table to
any piece of information in another table as long as the two tables share a common data
element (such as an employee number). Because relational DBMS can easily combine
information from different sources, they are more flexible than the other DBMS structures.
Access paths to data are not pre-specified, so they can easily respond to ad-hoc inquiries
with less extensive programming. The main problem with relational DBMS is poor
processing efficiency. Response time can be very slow if large numbers of accesses to
data are required to select, join, and extract data from tables. Developments in relational
technology, such as indexing, are starting to overcome this problem.
The hierarchical database model stores data logically in a vertical hierarchy resembling a
tree-like structure. An upper record is connected logically to a lower record in a parentchild relationship. A parent segment can have more than one child, but a child can only
have one parent. Hierarchical DBMS are good for treating one-to-many relationships. They
can store large numbers of segments and process information efficiently, but they can only
deliver information if a request follows the linkages of the hierarchy. Their disadvantages
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are their low user-friendliness, inflexibility, and programming complexity. They are good for
high-volume, rapid response systems, such as airline reservation systems.
The network model stores data logically in a structure that permits many-to-many
relationships. Through extensive use of pointers, a child segment can have more than one
parent. Network DBMS reduce redundancy and, like hierarchical databases, they process
information efficiently. However, they are inflexible and are very complex to maintain and
program.
The object-oriented DBMS stores data and the procedures acting on the data as objects
that can be automatically retrieved and shared. Object-oriented databases can store
complex types of information, but are slower at processing larger numbers of transactions
when compared to relational DBMS. Object-relational databases combine the capabilities
of the relational database with the storage capabilities of an object-oriented database.
10. Name and describe the three most important SQL commands.
The three most important SQL commands are SELECT, FROM, and WHERE. The
SELECT statement lists the columns from tables that will appear in the result table. The
FROM statement identifies the tables or views from which the columns will be selected.
The WHERE statement specifies the conditions for selecting specific rows within a single
table and conditions for joining multiple tables.
11. What is normalization? How is it related to the features of a well-designed relational
database?
Normalization is the process of creating small stable data structures from complex groups
of data when designing a relational database. Normalization streamlines relational
database design by removing redundant data such as repeating groups. A well-designed
relational database will be organized around the information needs of the business and will
probably be in some normalized form. A database that is not normalized will have
problems with insertion, deletion, and modification.
12. What is a distributed database, and what are the two main ways of distributing
data?
A distributed database is one that is stored in more than one physical location. A
distributed database can be partitioned or replicated. When partitioned, the database is
divided into partitions, so that each remote processor has access to the data that it needs
to serve its local area. These databases can be updated locally and later justified with the
central database. With replication, the database is duplicated at various remote locations.
Figure 7-15 shows how a database is distributed.
13. What are the four key organizational elements of a database environment? Describe
each briefly.
The four key organizational elements of a database environment are data administration,
data planning and modelling methodology, database technology and management, and
users. Data administration is the organizational function for managing the organization's
data resources and is concerned with information policy, data planning, maintenance of
data dictionaries, and data quality standards.
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A data planning and modelling methodology focuses on enterprise-wide planning and
analysis of data. The database technology and management element is responsible for
defining and organizing the structure and content of the database as well as maintaining
the database. The user element references the fact that end users have a wider role with
DBMS than in traditional systems and must be trained.
14. Describe the capabilities of online analytical processing (OLAP) and datamining.
Online analytical processing and datamining enable the manipulation and analysis of large
volumes of data from many perspectives, for example, sales by item, by department, by
store, by region, in order to find patterns in the data. Such patterns are difficult to find with
normal database methods, which is why a data warehouse and datamining are usually
parts of OLAP.
Datamining uses a variety of techniques to find hidden patterns and relationships in large
pools of data and to infer rules from them that can be used to predict future behavior and
guide decision making. For example, Hudson’s Bay Company uses datamining to analyze
data generated by visitors to its Web site. It uses the results to customize advertising and
content to individual customers and to improve online customer service.
15. What is a data warehouse? How can it benefit organizations?
A data warehouse is a database with archival, querying, and data exploration tools (i.e.,
statistical tools) and is used for storing historical and current data of potential interest to
managers throughout the organization and from external sources (e.g. competitor sales or
market share). The data originate in many of the operational areas and are copied into the
data warehouse as often as needed. The data in the warehouse are organized according
to company-wide standards so that they can be used for management reporting and
analysis. Data warehouses support looking at the data of the organization through many
views or directions. A data warehouse allows managers to look at products by customer,
by year, by salesperson, essentially different slices of the data. Normal operational
databases do not permit these different views.
16.
What is a hypermedia database? How does it differ from a traditional database?
How is it used for the Web?
Traditional databases store only homogeneous data that can be easily structured into
predefined data fields and records. They are not well suited for handling other types of
data such as procedures or graphics. Hypermedia databases store chunks of information
in linked nodes. These nodes can contain text, graphics, sound, full-motion video, or
executable computer programs. These databases are less structured than traditional
DBMS and contain a wider array of data. The nodes of a hypermedia database can be
linked in any kind of relationship established by the database creator. The hypermedia
database approach enables users to access topics on a Web site in whatever order they
wish. Web sites store information as interconnected pages containing text, sound, video,
and graphics using a hypermedia database.
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17. How can users access information from a company’s internal databases via the
Web?
The user uses Web browser software on his or her client PC to access a corporate Web
site over the Internet. The Web browser software requests data from the organization’s
database, using HTML commands to communicate with the Web server. Because many
back-end databases cannot interpret commands written in HTML, the Web server passes
these requests for data to special middleware software that then translates HTML
commands into SQL so that they can be processed by the DBMS working with the
database. The DBMS receives the SQL requests and provides the required data. The
middleware transfers information from the organization’s internal database back to the
Web server for delivery in the form of a Web page to the user. The software working
between the Web server and the DBMS can be an application server, a custom program,
or a series of software scripts.
Application Software Exercise
This exercise requires that students know how to create queries and reports using
information from multiple tables. The solutions provided here were created using the query
wizard and report wizard capabilities of Access. Students can of course create more
sophisticated reports if they wish.
The database would need some modification to answer other important questions about
the business. The owners might want to know, for example, which are the fastest-selling
bicycles. The existing database shows products in inventory and their suppliers. The
owners might want to add an additional table (or tables) in the database to house
information about product sales, such as the product identification number, date placed in
inventory, date of sale, purchase price, and customer name, address, and telephone
number. Management could use this enhanced database to create reports on best selling
bikes over a specific period, the number of bicycles sold during a specific period, total
volume of sales over a specific period, or best customers. Students should be encouraged
to think creatively about what other pieces of information should be captured in the
database that would help the owners manage the business.
Group Project
Review Figure 7-4, which provides an overview of a human resources database.
Some additional information that might be maintained in such a database are an
employee’s date of hire, date of termination, number of children, date of birth,
educational level, gender code, year-to-date gross pay and net pay, amount of life
insurance coverage, life insurance plan payroll-deduction amount, and pension plan
payroll-deduction amount.
Form a group with three or four of your classmates. Prepare two sample reports
using the data in the database that might be of interest to either the employer or the
employee. What pieces of information should be included in each report? In
addition, prepare a data dictionary entry for one of the data elements in the
database similar to the entry illustrated in Figure 7-5.
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Your group’s analysis should determine what business functions use this data
element, which function has the primary responsibility for maintaining the data
element, and which positions in the organization can access that data element. If
possible, use electronic presentation software to present your findings to the class.
Your students can relate to and understand the human resources database, so this
exercise should contribute to their understanding of the value of a database. Employee
pension and insurance benefits, employee contributions to pensions, employer pension
contributions, dates of hire, and employee termination are examples of reports. The pieces
of information that are necessary can be determined from the type of report. Social
insurance number is one data element that should appear on every report. Other data
elements are determined by the report.
Case Study – Cognos Gives Businesses Intelligence
1. What sort of data do you think Cognos can integrate and combine using its BI
software?
Technically, Cognos’ BI software should be able to integrate and combine data from all
functions of a corporation. For example, managers would be most interested in data from
transaction processing, sales, manufacturing and operations, and logistics.
2. Why would an organization want to use Cognos software? How would it know it was
worth the expense?
Cognos Software “slices and dices” data info multidimensional views that permit managers
to visualize exactly what is going on in their data, to transform that data from raw data to
information and then knowledge that can be used for decision making. Cognos software
brings together data from various sources in various formats to integrate it into a unified
whole picture. If a company was to increase their sales, reduce production costs, or even
be able to predict their demand and supply, they should feel that the expense of the
implementation was worth the cost.
3. What companies in your own province that are not mentioned above do you think
could make use of Cognos BI software? For what purposes?
Depending on the province, this question may have many different answers. Some
example companies could be: Great West Life Assurance Company, Shopper’s Drug Mart,
Best Buy, and Canada Safeway. Business intelligence software could help with defining
market niches for promotions and advertising campaigns as well as helping manage
inventory and ensure that each store had the right amount of inventory on hand.
4. Why do organizations have their data scattered in so many different databases and
so many different formats?
Segregated and dissimilar databases are caused by the implementation of different and
proprietary systems for a variety of business reasons. For example, marketing and sales
databases may store data in different formats than operational or manufacturing
databases.
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5. Would having all of a company’s data in one database and in one format eliminate
the need for BI software like that offered by Cognos? Why, or why not?
The BI software offered by Cognos not only brings together data from various sources in
various formats but also provides datamining capabilities such as managed reporting,
analysis, score carding, visualization, and event prediction and detection. Because of
these abilities and features, a company would require Cognos’ Bi software to transform the
data from raw data to information and then to knowledge to attain some value from this
system.
6. Are there any ethical problems that might arise from the use of Cognos BI
software? If so, what are they?
Some individuals might believe that the lines between business intelligence and
competitive intelligence are blurred. Competitive intelligence involves data and information
on competitors in the same or similar industries. This information can be seen as unethical
by some who believe that each company should only have access to publicly-available
information, which keeps the competitive playing field equal.
Also, data on individuals may be used for purposes other than those originally intended by
the individuals, such as selling the data to third parties or even using the data in-house to
offer coupons personalized at check out.
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Management Information Systems, Second Canadian Edition
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