Accounting information systems 12th SIMKIN and norman chapter 03
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Chapter 3:
Data Modeling
Introduction
An Overview of Databases
Steps in Developing a Database Using
Resources, Events and Agents Model
Normalization
Chapter
3-1
Introduction
Uses of a modern AIS
Systematically
Provide
Easy
record data
convenient and useful formats
access to information
Chapter
3-2
What is a Database?
Collection of organized data
Used by many different computer
applications
Manipulated by database management
systems (DBMS)
Chapter
3-3
Significance of a Database
Critical information
Volume
Distribution
Privacy
Irreplaceable data
Need for accuracy
Internet uses
Chapter
3-4
Storing Data in Databases
Data must be stored and organized
systematically
Three important concepts:
Data hierarchy
Record structures
Database keys
Chapter
3-5
Data Hierarchy
Data organization in ascending order:
Data
field
Record
File
Database
Chapter
3-6
Record Structures
Data fields in each record of a database table
Structure is usually fixed
Example
Chapter
3-7
Database Keys
Primary Key
Unique
to each record
Foreign Keys
Enable
referencing of one or more records
Matches
primary key of related table
Chapter
3-8
Records Combined Into
Report
Chapter
3-9
Additional Database Issues
Administration
Database
Administrator
Documentation
Includes
a variety of descriptions
Structures, Contents, Security Features
Data Dictionary
Metadata
Chapter
3-10
Data Dictionary Example
Chapter
3-11
Additional Database Issues
Data Integrity
Data
Integrity controls
Designed by database developers
Processing Accuracy and Completeness
Transaction
controls
Ensures accurate transaction processing
Chapter
3-12
Additional Database Issues
Concurrency
Concurrency
controls
Prevent multi-user access at same time
Backup and Security
Ability
to recreate data
Prevent unauthorized access
View controls
Chapter
3-13
Study Break #1
The part of the data hierarchy that represents one instance of
an entity is a:
A. Field
B. Record
C. File
D. Database
Chapter
3-14
Study Break #1 - Answer
The part of the data hierarchy that represents one instance of
an entity is a:
A. Field
B. Record
C. File
D. Database
Chapter
3-15
Study Break #2
Within the context of databases, the term “concurrency” refers
to the possibility that:
A. A customer of one store might also be a customer of another
store
B. Two database users might want to access the same record at
the same time
C. A credit entry for a customer requires a debit entry for a
matching account
D. None of these
Chapter
3-16
Study Break #2 - Answer
Within the context of databases, the term “concurrency” refers
to the possibility that:
A. A customer of one store might also be a customer of another
store
B. Two database users might want to access the same record at
the same time
C. A credit entry for a customer requires a debit entry for a
matching account
D. None of these
Chapter
3-17
REA Model
Resources
Organization’s assets
Events
Activities associated with a business processes
Agents
People associated with business activities
Chapter
3-18
Steps in Developing
Databases with REA
Identify Business and Economic Events
Identify Entities
Identify Relationships Among Entities
Chapter
3-19
Steps in Developing
Databases with REA
Create Entity-Relationship Diagrams
Identify Attributes of Entities
Convert E-R Diagrams into Database Tables
Chapter
3-20
Identify Events and Entities
Types of Events
Business
Economic
Types of Database Entities
Entities
Agents
Resources
Chapter
3-21
Entity Examples
Chapter
3-22
Identify Relationships
Among Entities
Types of Relationships
Direct relationship
Indirect relationship
Cardinalities
Nature of relationships among entities
Chapter
3-23
Cardinality Relationships
Notations
One-to-one (1:1)
One-to-many (1:N)
Many-to-many (N:N)
Purpose
Occurrence of one entity
Associated with occurrence of one event of another entity
Chapter
3-24
Cardinality Relationships
Chapter
3-25
