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Using MIS 3e
Chapter 5
Database Processing
David Kroenke
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Businesses of every size organize data records into collections called databases. At one
extreme, small businesses use databases to keep track of customers; at the other extreme,
huge corporations such as Dell and Amazon.com use databases to support complex sales,
marketing, and operations activities. In between, we have businesses like FlexTime that use
databases as a crucial part of their operations, but they don’t have a trained and experienced
staff to manage and support the databases. To obtain answers to the one-of-a-kind queries he
needs, Neil needs to be creative and adaptable in the way that he accesses and uses his
database.
This chapter discusses the why, what, and how of database processing. We begin by
describing the purpose of databases and then explain the important components of database
systems. We then overview the process of creating a database system and summarize your
role as a future user of such systems.
Users have a crucial role in the development of database applications. Specifically, the
structure and content of the database depends entirely on how users view their business
activity. To build the database, the developers will create a model of that view using a tool
called the entity-relationship model. You need to understand how to interpret such models,
because the development team might ask you to validate the correctness of such a model
when building a system for your use. Finally, we describe the various database administration
tasks.
This chapter focuses on database technology. Here we consider the basic components of a
database and their functions. You will learn about the use of database reporting and data
mining in Chapter 9.
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Study Questions
Q1 What is the purpose of a database?
Q2
What is a database?
Q3
What are the components of a database application system?
Q4
How do database applications make databases more useful?
Q5
How are data models used for database development?
Q6
How is a data model transformed into a database design?
Q7
What is the users’ role in the development of databases?
Q8
2020?
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What Is the Purpose of a
Database?
• Purpose: to keep track of things
• If structure of a list is simple, i.e., one theme,
no need to use database technology (video)
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Form for Recording Multiple
Themes
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General Rule
• Lists of data involving a single theme can be
stored in a spreadsheet.
• Lists that involve data with multiple themes
require a database.
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Study Questions
Q1
What is the purpose of a database?
Q2 What is a database?
Q3
What are the components of a database application system?
Q4
How do database applications make databases more useful?
Q5
How are data models used for database development?
Q6
How is a data model transformed into a database design?
Q7
What is the users’ role in the development of databases?
Q8
2020?
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Database
• Database:
 A self-describing collection of integrated
records
 In databases, bytes are grouped into
columns, such as Student Number and
Student Name. Columns are also called
fields. Columns or fields, in turn, are
grouped into rows, which are also called
records.
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Characters, Fields, and Records
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Hierarchy of Data Elements
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Metadata Describes Structure of
Database
Components of a Database
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What Are Relationships Among
Rows?
First row of the Email Table is
related to Andrea Baker in
Student Table
Last row in Office_Visit Table
related to Adam Verberra in
Student Table
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Relationship Special Terms
• Key
 A column or group of columns that identifies a unique row in
a table.
 Student Number is the key of the Student table. Given a
value of Student Number, you can determine one and only
one row in Student. Only one student has the number 1325.
 Every table must have a key.
 Sometimes more than one column is needed to form a
unique identifier. In a table called City, for example, the key
would consist of combination of columns (City, State).
 Email_Num is the key of Email Table.
 VisitID is the key of Office_Visit Table.
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Relationship Special Terms
• Foreign keys
 These are keys of a different (foreign) table
than the table in which they reside.
• Relational databases
 Relationships among tables are created by
using foreign keys.
• Relation
 Formal name for a table
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Metadata
• Database:
 A database is a
self-describing
collection of
integrated
records.
• Metadata
 Data that
describe data
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Study Questions
Q1
What is the purpose of a database?
Q2
What is a database?
Q3 What are the components of a database
application system?
Q4
How do database applications make databases more useful?
Q5
How are data models used for database development?
Q6
How is a data model transformed into a database design?
Q7
What is the users’ role in the development of databases?
Q8
2020?
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Components of a Database
Application System
• Applications make database data more accessible and useful.
• Users employ a database application that consists of forms,
formatted reports, queries, and application programs.
• Database management system (DBMS) processes database
tables for applications.
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What Is a Database Management
System (DBMS)?
• DBMS
 A program (software) used to create, process, and administer
a database
• Companies license DBMS products from vendors:
 IBM, Microsoft, Oracle, and others
• Popular DBMS products are:
 DB2 from IBM
 Access and SQL Server from Microsoft
 Oracle from the Oracle Corporation
 MySQL—an open-source DBMS product that is license-free
for most applications
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Creating the Database and Its
Structures
• Database developers use the DBMS to create and modify tables,
relationships, and other structures in the database.
• Below, the developer has added a new column called
Response?. This new column has data type Yes/No.
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Processing the Database
• DBMS operations
 Read, insert, modify, delete data
 Applications call DBMS in different ways
• From a form, when the user enters new or
changed data, a computer program behind the
form calls the DBMS to make the necessary
database changes.
• From an application program, the program calls
the DBMS directly to make the change.
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Structured Query Language (SQL)
• SQL—“see-quell”
• International standard language for creating
databases and database structures, and processing
databases
• All five of the most popular DBMS products accept
and process SQL.
• Following SQL statement inserts a new row into the
Student table:
INSERT INTO Student
([Student Number], [Student Name], HW1, HW2, MidTerm)
VALUES
(1000, ’Franklin, Benjamin’, 90, 95, 100);
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Administering the Database
• DBMS provides tools to assist in administration of the
database.
• Used to set up a security system involving user
accounts, passwords, permissions, and limits for
processing the database
• Backing up database data, adding structures to
improve performance of database applications,
removing data no longer wanted or needed, and
similar tasks
• Most organizations dedicate one or more employees
to the role of database administration.
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Major Responsibilities of
Database Administration
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Study Questions
Q1
What is the purpose of a database?
Q2
What is a database?
Q3
What are the components of a database application system?
Q4 How do database applications make
databases more useful?
Q5
How are data models used for database development?
Q6
How is a data model transformed into a database design?
Q7
What is the users’ role in the development of databases?
Q8
2020?
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Database Applications at
FlexTime
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What Are Forms, Reports, and
Queries?
Reports show data in a
structured context.
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What Are Forms, Reports, and
Queries?
Sample query
form used
to enter
phrase for
search
Sample query results of query operation
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Why Are Database Application
Programs Needed?
• Forms, reports, and queries work well for standard
functions. However, most applications have unique
requirements that a simple form, report, or query
cannot meet.
• Application programs process logic that is specific to
a given business need.
• Application programs serve as an intermediary
between the Web server and database.
 Responds to events, such as when a user presses
a submit button; also reads, inserts, modifies, and
deletes database data
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Four Database Application
Programs Running on a Web
Server Computer
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Multi-User Processing Problem
• Lost-update problem
 Process A reads a customer record from a file containing account
information, including the customer’s account balance and phone
number.
 Process B now reads the same record from the same file so it has
its own copy.
 Process A changes the account balance in its copy of the customer
record and writes the record back to the file.
 Process B—which still has the original stale value for the account
balance in its copy of the customer record—updates the customer’s
phone number and writes the customer record back to the file.
 Process B has now written its stale account balance value to the file,
causing the changes made by process A to be lost.
(Source: http://en.wikipedia.org/wiki/File_locking)
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Enterprise DBMS vs. Personal
DBMS
• Enterprise DBMS
•
 Process large organizational and workgroup databases
 Support many, possibly thousands, of users and many different
database applications
 Support 24/7 operations and can manage databases that span
dozens of different magnetic disks with hundreds of gigabytes or
more of data
 IBM’s DB2, Microsoft’s SQL Server, and Oracle’s Oracle are
examples of enterprise DBMS products.
Personal DBMS
 Designed for smaller, simpler database applications
 Used for personal or small workgroup applications that
involve fewer than 100 users (normally fewer than 15), single
user
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Access: A DBMS and an
Application Development Product
Before building a database, developers construct a logical
representation of database data called a data model to describe the
data and relationships to be stored in database.
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Study Questions
Q1
What is the purpose of a database?
Q2
What is a database?
Q3
What are the components of a database application system?
Q4
How do database applications make databases more useful?
Q5 How are data models used for database
development?
Q6
How is a data model transformed into a database design?
Q7
What is the users’ role in the development of databases?
Q8
2020?
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Database Development Process
(video link needed)
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What Is the Entity-Relationship
Data Model?
• Entity-relationship (E-R) data model
 A tool for constructing data models
 Developers use it to describe the content of a data
model by defining entities that will be stored in
database and relationships among those entities
 Unified Modeling Language (UML), less popular,
tool for data modeling
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Entities
• Some thing that the users want to track
• Examples of entities:
 Order, Customer, Salesperson, and Item. Some entities represent a
physical object, such as Item or Salesperson; others represent a
logical construct or transaction, such as Order or Contract.
 Entity names are always singular.
• Attributes
 Describe characteristics of an entity.
 Examples: order attributes are OrderNumber, OrderDate, SubTotal,
Tax, Total, and so forth.
• Identifier
 An attribute (or group of attributes) whose value is associated with
one and only one entity instance.
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Student Data Model Entities
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Entities with Relationships
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Sample Relationship (Version 1)
Crow’s
Feet
1:N
N:M
1:N = many-to-many
relationships
N:M = many-to-many
relationships
One department can have
many advisers, but an adviser
has at most one department.
One adviser can have many
students and one student can
have many advisers.
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Sample Relationships (Version 2)
Advisers may advise in more than one department, but a
student may have only one adviser, representing a policy that
students may not have multiple majors.
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Crow’s-Foot Diagram Version
Maximum cardinality—maximum number of entities that can be
involved in a relationship. Vertical bar on a line means that at least one
entity of that type is required.
Minimum cardinality—minimum number of entities that can be involved
in a relationship. Small oval means that the entity is optional; the
relationship need not have an entity of that type.
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Study Questions
Q1
What is the purpose of a database?
Q2
What is a database?
Q3
What are the components of a database application system?
Q4
How do database applications make databases more useful?
Q5
How are data models used for database development?
Q6 How is a data model transformed into a
database design?
Q7
What is the users’ role in the development of databases?
Q8
2020?
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Database Design
• Database design is the process of converting a data
model into tables, relationships, and data
constraints.
• Database design team transforms entities into tables
and expresses relationships by defining foreign keys.
• Two important database design concepts:
normalization and the representation of two kinds
of relationships.
• Normalization is a foundation of database design.
• Representation of relationships will help you
understand important design considerations.
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Normalization
Normalization is the process of converting a poorly structured table into
two or more well-structured tables. Problem with these tables, have two
independent themes: employees and departments.
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Data Integrity Problems
• In previous figure, some rows show Dept. 100 is “Accounting and
Finance” and others show Dept. 100 is “Accounting.” Which one
is correct?
• A table with data integrity problems will produce incorrect results
and inconsistent information.
• Data integrity problems happen when data are duplicated.
• Users will lose confidence in the information, and system will
develop a poor reputation. Information systems with poor
reputations become serious burdens to the organizations that
use them.
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Normalizing for Data Integrity
• Normalized tables eliminate data duplication,
but they can be slower to process.
• General goal of normalization is to construct
tables such that every table has a single topic
or theme.
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Normalizing for Data Integrity
• The way to correct the problem is to split the table into two
tables, each with its own theme.
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Summary of Normalization
• Database practitioners classify tables into various
normal forms according to the kinds of problems they
have.
• Transforming a table into a normal form to remove
duplicated data and other problems is called
normalizing the table.
• Normalization is just one criterion for evaluating
database designs. Normalized designs can be slower
to process, database designers sometimes choose to
accept nonnormalized tables. The best design
depends on the users’ processing requirements.
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Representing Relationships
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Representing
a 1:N
Relationship
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Representing an N:M
Relationship
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Study Questions
Q1
What is the purpose of a database?
Q2
What is a database?
Q3
What are the components of a database application system?
Q4
How do database applications make databases more useful?
Q5
How are data models used for database development?
Q6
How is a data model transformed into a database design?
Q7 What is the users’ role in the
development of databases?
Q8
2020?
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Users’ Role
• Users are the final judges of:
 What data the database should contain,
 How tables should be related.
• Users review data model to be sure it accurately
reflects users’ view of the business.
 Mistakes will come back to haunt you.
• Easiest time to change database structure is during
data modeling stage. Changing a relationship from
one-to-many to many-to-many in a data model is
simply a matter of changing the 1:N notation to N:M.
• User review of the data model is crucial.
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Study Questions
Q1
What is the purpose of a database?
Q2
What is a database?
Q3
What are the components of a database application system?
Q4
How do database applications make databases more useful?
Q5
How are data models used for database development?
Q6
How is a data model transformed into a database design?
Q7
What is the users’ role in the development of databases?
Q8 2020?
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Data Aggregators
• Acxiom obtain data from public and private sources and store
and process it in sophisticated ways.
• Use your grocery store club card, that data is sold to a data
aggregator. Credit card data, credit data, public tax records,
insurance records, product warrantee card data, voter
registration data, and hundreds of other types of data are sold to
aggregators.
• Using a combination of phone number, address, email address,
name, and other partially identifying data, such companies can
integrate that disparate data into an integrated, coherent whole
to form detailed descriptions about companies, communities, zip
codes, households, and individuals.
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Data Aggregators
• Laws that limit the data that federal and other
governmental agencies can acquire and store.
• Some legal safeguards on data maintained by credit
bureaus and medical facilities.
• No such laws that limit data storage by most
companies (nor are there laws that prohibit
governmental agencies from buying results from
companies like Acxiom.
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How Will this Change by 2020?
• Absent any public outcry for legislation to limit such
activity, aggregator data storage will continue to grow
exponentially and companies will have even more
data about you, the state of your health, your wealth,
your purchase habits, your family, your travel, your
driving record, and, well, anything you do.
• Query, reporting, and data mining technology will
improve and Moore’s law will make computer
operations that are too slow to be practical today,
feasible tomorrow.
• The picture of you will become more and more
detailed.
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Why Do You Care?
• Data could be stolen and used for criminal
activity against you.
• Data might not be accurate.
• No organization is required by law to tell you
the data that it stores about you and what it
does with it.
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What If…
• You enroll in a “healthy eaters” medical
insurance program, similar to “safe drivers”
auto insurance. Your premiums are lower
because you eat well, except that the
insurance company notes from last month’s
data that you bought four large packages of
Cheetos, and your health insurance premium
is increased, automatically. You have no idea
why.
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Ethics Guide: Nobody Said I
Shouldn’t
• Kelly was employed maintaining servers and
backing up database.
 Made copy of database to practice with
• Queried SQL server metadata
• Discovered tables with order data, customers,
salespeople
• Uncovered anomalies—one entry clerk gave
discounts to a buyer that no other clerks gave
discounts to
 Mentioned it to a clerk
 Was terminated for accessing database
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Ethics Guide: Nobody Said I
Shouldn’t
• Where did Kelly go wrong?
• Was it illegal, unethical, or okay for Kelly to
copy the database and take it home?
• How should Kelly have handled his discovery
of the anomaly better?
• Does Kelly have any legal recourse over
being fired?
• How can a business protect its databases
from unauthorized use?
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Guide: No, Thanks, I’ll Use a
Spreadsheet
• Databases take time to build.
• Complicated to operate
 May require use of multiple applications
• Need IS people to create it and keep it
running
• Will share data that you may not want to
expose
• Spreadsheets may be a better option in some
cases.
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Guide: Immanuel Kant, Data
Modeler
• What we perceive as reality is based on our
perceptive apparatus. That which we perceive
he called phenomena.
• Our perceptions, such as of light and sound,
are processed by our brains and made
meaningful.
• But we do not and cannot know whether the
images we create from the perceptions have
anything to do with what might or might not
really be.
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Guide: Immanuel Kant, Data
Modeler
• Noumenal world refers to the essence of “things in
themselves”—to whatever it is out there that gives rise
to our perceptions and images.
• Phenomenal world refers to what we humans
perceive and construct.
• Easy to confuse the noumenal world with the
phenomenal world, because we share the
phenomenal world with other humans.
• Shared mutual view does not mean that the mutual
view describes the “real world.”
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Guide: Immanuel Kant, Data
Modeler
• Nothing that humans can do represents the real, noumenal
world. A data model, therefore, is a model of a human’s
model of what appears to be “out there.”
• Data models do not model “the real world.” A data model is
simply a model of what the data modeler perceives.
• Must ask the question, “How well does the data model fit
the mental models of the people who are going to use the
system.”
• Only valid point is whether it reflects how users view their
world. Will it enable the users to do their jobs?
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Active Review
Q1
What is the purpose of a database?
Q2
What is a database?
Q3
What are the components of a database application system?
Q4
How do database applications make databases more useful?
Q5
How are data models used for database development?
Q6
How is a data model transformed into a database design?
Q7
What is the users’ role in the development of databases?
Q8
2020?
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Case Study 5: Benchmarking,
Bench Marketing, or Bench
Baloney
•
•
•
•
•
PC-Magazine test compared five DBMS products:
 DB2 (from IBM)
 MySQL (a free, open source DBMS)
 Oracle (from Oracle Corporation)
 SQL Server (from Microsoft)
 ASE (from Sybase Corporation)
SQL Server’s performance was worst performer.
Microsoft complained, so PC-Magazine reran the test using Microsoftsupporting software. SQL server performed best this time.
However, the second test compares apples and oranges.
Do benchmarks really mean anything? How should customers use
benchmarks?
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retrieval system, or transmitted, in any form or by any means, electronic,
mechanical, photocopying, recording, or otherwise, without the prior written
permission of the publisher. Printed in the United States of America.
Copyright © 2011 Pearson Education, Inc.
Publishing as Prentice Hall
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