Using MIS 2e
Chapter 5
Database Processing
David Kroenke
© Pearson Prentice Hall 2009
5-1
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 user’s role in the development of databases?
Q8 – What are the responsibilities for database administration?
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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 user’s role in the development of databases?
Q8 – What are the responsibilities for database administration?
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Q1 – What is the purpose of a database?
As a database user, you play a crucial role in developing database
applications for your business or organization.
Spreadsheets are good for tracking items with just one theme (as
shown below) versus a database that tracks things involving more
than one theme (as shown on the next slide).
Fig 5-1 List of Student Grades, Presented in a Spreadsheet
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Q1 – What is the purpose of a database?
Fig 5-2 Student Data Shown in a Form, from a Database
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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 user's role in the development of databases?
Q8 – What are the responsibilities for database administration?
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Q2 – What is a database?
These are terms you’ll need
to know when working with
databases.
A database is a self-describing
collection of integrated records.
Bytes, characters of data, are
grouped into columns which
are also called fields.
The fields are grouped into
rows which are also called
records.
A table is a group of similar
rows or records which is also
called a file.
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Fig 5-3 Student Table (also
called a file)
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Q2 – What is a database?
This figure shows the hierarchy of data elements working from the
smallest at the bottom to the largest at the top.
Fig 5-4 Hierarchy of Data Elements
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Q2 – What is a database?
A database is more than just a group of tables. It
includes tables or files plus the relationships among rows
in the tables and metadata that describes the database’s
structure.
Fig 5-5 Components of a Database
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Q2 – What is a database?
This diagram shows
relationships among
rows of different
tables.
The Student
Number value in the
first row of the top
table,1325, relates
to the same Student
Number value in a
row in the second
table.
Both that Student
Number value and
that of 4867 in the
second table relate
to those in the third.
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Fig 5-6 Example of Relationships Among Rows
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Q2 – What is a database?
Keys are a column that identifies a unique row in a table. In the
Student Table, the primary key is Student Number.
A primary key, Student Number, can act as a foreign key in a
different table, like the Office Visit Table.
A relational database
carries data in the
form of tables and
uses foreign keys
to represent relationships
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Q2 – What is a database?
Metadata are data that describe data and makes databases easy to
use. Metadata is always a part of a database.
The Field Name, Data Type, and Description at the top of this
diagram are part of the database’s metadata.
The additional
field properties
at the bottom
are also
considered
metadata.
Fig 5-7 Sample Metadata (in Access)
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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 user's role in the development of databases?
Q8 – What are the responsibilities for database administration?
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Q3 – What are the components of a database application system?
By itself, a database is not very useful because there’s no way to
easily manage the data and turn it into useful information.
A database application system makes database data more
accessible and useful by using forms, formatted reports, queries,
and application programs to provide useful information to users.
Fig 5-8 Components of a Database Application System
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Q3 – What are the components of a database application system?
A DBMS program is used to create, process, and administer a
database.
Popular DBMS products include:
DB2 from IBM
Access from Microsoft (for personal computers)
SQL Server from Microsoft (for large computer systems)
Oracle from Oracle Corporation
MySQL, an open-source product that’s license-free
It’s easy to confuse a DBMS, which is a software program,
with a database, which is a collection of tables, relationships
and metadata. But, they are two different concepts.
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Q3 – What are the components of a database application system?
A DBMS is used to create or modify tables, relationships, and other
structures in a database.
This figure shows how the metadata in an existing table is modified
to add a new field labeled “Response?”
Fig 5-9 Adding a New Column to a Table (in Access)
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Q3 – What are the components of a database application system?
DBMSs are used to process databases by reading, inserting,
modifying, or deleting data.
The Structured Query Language (SQL), is an international
standard language used by most major DBMS programs for
processing databases.
A DBMS includes tools to help you administer a database.
You can
Set up a security system that includes permissions and
passwords.
Back up the data to prevent it from being lost or compromised.
Improve the performance of applications by adding structures.
Remove data that’s no longer needed.
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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 user's role in the development of databases?
Q8 – What are the responsibilities for database administration?
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5-18
Q4 – How do database applications make databases more useful?
A database application includes forms, reports, queries, and
applications programs available to one or more users.
This figure shows three different applications stemming from a
single DBMS and a single database.
Fig 5-10 Use of Multiple Database Applications
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Q4 – How do database applications make databases more useful?
Data entry forms are used
to read, insert, modify, and
delete data.
Reports are used to show
data in a structured context
as the example to the right
shows.
Fig 5-11 Example of a Student Report
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Q4 – How do database applications make databases more useful?
A query form helps the user
quickly find answers to
questions. In this case, the
words “barriers to entry”
were found in Baker’s
record.
Fig 5-12 (a) & (b) Sample Query and Results
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Q4 – How do database applications make databases more useful?
Database application programs process logic specific to a given
business need. For example, a program could track backordered
items and hold a customer order until the items are ready to ship.
Application programs enable database processing over the Internet
as the figure below shows. Users access the applications programs
on a Web server, which in turn accesses a single DBMS and
database.
Fig 5-13 Four Application Programs on a Web Server Computer
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Q4 – How do database applications make databases more useful?
This figure depicts multi-user database processing. The
system must be managed properly to avoid the following
problems:
Potential update loss because two users update same data at the
same time
Potential locking problems
Possible data conflicts
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Q4 – How do database applications make databases more useful?
Here’s a comparison of an Enterprise DBMS versus a Personal DBMS.
Enterprise DBMS
Large organizational and
workgroup databases
Thousands of users
Many different database
applications
24/7 operations
DB2, SQL Server, Oracle
Personal DBMS
Smaller, simpler
applications
Personal or small
workgroup applications
Fewer than 100 users
Microsoft Access is both
a DBMS and application
development product as
this figure depicts.
Fig 5-14 Personal Database System
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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 user's role in the development of databases?
Q8 – What are the responsibilities for database administration?
© Pearson Prentice Hall 2009
5-25
Q5 – How are data models used for database development?
User involvement is critical for database development for these
reasons:
A database’s design depends on how users view their business
environment and how they do their jobs.
Database developers do not and cannot know what to include because
they don’t work with the data everyday. They must rely on users to tell
them what data are important and how they’re used.
A data model is similar to blueprints for a house. It’s a logical
representation of database data that describes data and their
relationships.
Fig 5-15 Database Development Process
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Q5 – How are data models used for database development?
An entity-relationship data model helps developers define things
(entities) that will be stored in the database as they are building a
data model. It also defines relationships among those entities.
Entities are things users want to track. It can be a physical object
(inventory items) or a logical transaction (sales order). The names
are always singular.
Each entity has attributes that describe its characteristics. The entity
“Order” has attributes like “OrderNumber” and “OrderDate”.
An identifier is an attribute whose value is associated with one and
only one entity instance. “OrderNumber” is the identifier for the
“Order” entity because there should only be one number for each
order.
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Q5 – How are data models used for database development?
Student, Department, Advisor, Email, and Office_Visit are the entity
names in this model.
The entity identifiers are StudentNumber, DeptName, and
AdvisorName. Not all entities require an identifier.
Fig 5-16 Student Data Model Entities
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Q5 – How are data models used for database development?
Relationships join one
entity to another entity
One-to-one – 1:1
One-to-many – 1:N
Many-to-many – N:M
This diagram shows that
each Department Entity
can have multiple Adviser
Entities in a one-to-many
relationship. Adviser
Entities can have a
many-to-many
relationship with Student
Entities.
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Q5 – How are data models used for database development?
The line style between entities describes the type of relationship as
shown in the entity-relationship diagram below.
This diagram depicts crow’s feet between the entities to describe the
relationships. It shows a one-to-many (1:M) relationship between
Department and Adviser and a many-to-many (N:M) relationship
between Adviser and Student entities.
Fig 5-19 Sample Relationships – Version 1
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Q5 – How are data models used for database development?
The entity-relationship diagram below shows a many-to-many (N:M)
relationship between Department and Adviser and a one-to-many
(1:M) relationship between Adviser and Student.
Because relationships among entities can vary, only the user can
describe the entity-relationship. That’s why it’s so important for
users to help design databases.
Fig 5-19 Sample Relationships – Version 2
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Q5 – How are data models used for database development?
Maximum cardinality represents the maximum number of entities
that can be involved in a relationship.
Minimum cardinality represents the minimum number of entities that
can be involved in a relationship.
The vertical bar below indicates that at least one entity is required
between Department and Adviser and between Adviser and Student.
The oval below indicates that an entity is optional and doesn’t
require a relationship.
Fig 5-20 Sample Relationships Showing Maximum/Minimum Cardinality
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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 user's role in the development of databases?
Q8 – What are the responsibilities for database administration?
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Q6 How is a data model transformed into a database design?
Converting a poorly structured table into two or more well-structured
tables is called normalization.
The table below is poorly designed because it includes the
DeptName as part of the Employee record, making it difficult to
update.
It also creates data integrity
problems because
the DeptName is not
consistent throughout
the table after the
data were updated.
Fig 5-21 Poorly Designed Employee Table
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Q6 How is a data model transformed into a database design?
Normalizing the tables by splitting the Department data into a
separate table, as shown below, allows each table to describe a
single topic or theme. The tables have been transformed into a
normal form.
By eliminating the duplicate data, you eliminate data integrity
problems. That’s called
normalizing for data integrity.
Now, the department
name only needs to
be updated in one place
in the normalized tables.
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Q6 How is a data model transformed into a database design?
This chart shows the necessary steps to transform a
data model into a relational database design.
Fig 5-23 Transforming a Data Model into a Database Design
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Q6 How is a data model transformed into a database design?
The figures below and on the next slide depict the steps used to
create a well structured database that will produce useful
information.
The figure on the left represents the relationship between tables.
The figure on the right shows a normalized table for each entity.
From Figure 5-24 Representing a 1:N Relationship
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Q6 How is a data model transformed into a database design?
The figure below shows how relationships are represented using
foreign keys. It’s the last step in transforming a data model into a
database design.
From Figure 5-24 Representing a 1:N Relationship
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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 user's role in the development
of databases?
Q8 – What are the responsibilities for database administration?
© Pearson Prentice Hall 2009
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Q7 – What is the user's role in the development of databases?
Your role in the database development process is to decide what
data should be included and how records should relate to one
another.
The best time to change a database structure is during the data
modeling stage. It’s easier and cheaper to change your mind before
anything is actually built. The costs of correcting the database in
time and money later on may be very high.
Each entity must contain all the data you need to do your job.
Each relationship must accurately reflect the appropriate view of
your business.
You must be the final judge of how well the database will serve your
needs. Do not go forward until the data model is accurate.
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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 user's role in the development of databases?
Q8 – What are the responsibilities for database
administration?
© Pearson Prentice Hall 2009
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Q8 – What are the responsibilities for database administration?
Databases are an important resource for most
businesses.
As databases touch more aspects of systems and
business functions, the utility of a database increases as
do potential problems.
Database administration manages the development,
operation, and maintenance of databases.
Database administration must protect the database and
maximize its availability for authorized use.
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Q8 – What are the responsibilities for database administration?
Database administration tasks are divided into four
categories as shown below and on the next slide.
Fig 5-26 Summary of Database Administration Tasks
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Q8 – What are the responsibilities for database administration?
Fig 5-26 Summary of Database Administration Tasks, continued
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