Information Resources
Management
January 16, 2001
Agenda
Administrivia
 Course Overview
 Database Management Systems
(DBMSs)
 Homework #1

Administrivia
Syllabus
 Book
 Homework
 Web Page

Course Calendar
Eleven Homeworks
 Approximately one per week
 Exams
 Midterm 1 - 2/20
 Midterm 2 - 3/20
 Final - TBA
 Quizzes
 Up to five

Overview – Perspective
Database Design and Implementation
 “Business” Perspective
 IT professional in an organization

Database Design
Relational Model
 Database Modeling
 Evaluation Tools
 Normalization

Database Implementation
SQL (Structured Query Language)
 Dependability, Reliability
 Architecture
 Distributed Databases

Database Management
Systems
Traditional File Processing Systems
 Database
 Comparison
 Database Lifecycles
 Database Management System
Functions

Traditional File Processing
System
Separate Files
 Department
 Business Function
 Independent of Each Other
 High Level of Program Dependence
 Program contains file structure and
location

Example
Time Cards
Data
Entry
Trans
Trans
Sort by
Employee
#
Sorted by
Employee
#
Master
Update
Master
Report
Checks
New
Master
Data Abstraction (Views)

Physical/Internal

How data is stored

Logical/Conceptual

What is stored

View/External

What is used
(subset)
Traditional file processing prevents
this abstraction. Why?
Three Views of Data
External
(View)
Conceptual
(Logical)
Internal
(Physical)
Client
Customer
Designer
Database
Administrator
(DBA)
Programmer
Database
Administrator
(DBA)
Tech Support
What is Needed
Physical Independence
 Logical Independence

Physical Independence
Physical layout and organization of data
can be changed without changing either
the overall logical structure of the data
or the application programs
 Examples
 Move data location
 Move data to faster storage
 Change indexing
 Add a secondary key

Physical Independence
External
(View)
Conceptual
(Logical)
No Resulting
Change Here
Internal
(Physical)
Change Here
Logical Independence
Non-loss changes to the logical structure
can be made without changing application
programs or end-user views
 Examples
 Change format of a field (zip from 5 to 9)
 Add a new data field
 Add a new table
 Divide a table into two

Logical Independence
External
(View)
No Resulting
Change Here
Conceptual
(Logical)
Change Here
Internal
(Physical)
Coordinating
Change Here
Database
organized collection of logically related
data
 shared collection of interrelated data
designed to meet the informational needs
of multiple users
 data is independent of program and user
views
 data is stored with physical and logical
independence

Database Management
System (DBMS)

Software that facilitates the
implementation of the database concept
Comparison
(Traditional vs. Database)

Database Advantages/Traditional
Disadvantages
 program-data dependence
 duplication
 data sharing
 development times
 program maintenance – ripple effects
 flexibility
Comparison
(Traditional vs. Database)

Database Advantages/Traditional
Disadvantages
 security
 data integrity
 data as corporate resource
Comparison
(Traditional vs. Database)

Traditional Advantages/Database
Disadvantages
 size
 complexity
 cost
 special hardware
 impact of failure
 recovery
Comparison
(Traditional vs. Database)

Traditional Advantages/Database
Disadvantages
 additional personnel
 conversion costs
 organizational conflict
Database Lifecycle
1. Enterprise Modeling
2. Conceptual Data Modeling
3. Logical Database Design
4. Physical Database Design and
Creation
5. Database Implementation
6. Database Maintenance
People Involved
Systems analysts & designers
 Database analysts & designers
 Users
 Programmers
 Database Administrators (DBAs)
 Networking experts
 Other technical experts

Database Management
System Functions
data storage, retrieval and update
 user-accessible catalog
 transaction support
 concurrency control
 recovery services
 authorization services
 support for data communication

Database Management
System Functions
integrity services
 types - character, number, etc.
 internal validity
 services to promote data independence
(logical and physical)
 utility services

Database Applications
Personal
 one user
 Workgroup
 small team - LAN connected
 Department/Division
 multiple teams and functions
 Enterprise
 entire organization

In-Class Exercise
Groups of 4
 Introduce yourself
 Identify a possible database of each
type
 Pick a speaker

In-Class Exercise
Introduce yourself and group members
 Give group’s example databases
 personal
 workgroup
 department/division
 enterprise

Personal Databases

Benefits
 individualized
 meet specific
needs
 purchased
package

Drawbacks
 limited to no data
sharing
 replicated data
 consolidation standardization
 support
Workgroup Databases

Benefits
 meet specific
needs
 data shared
(across group)
 customized
“views”

Drawbacks
 data sharing
across groups
 replicated data
 security
 not optimal for
individual
 DBMS cost &
support
Department Databases

Benefits
 meet (specific)
needs
 data shared

Drawbacks
 data sharing
 replicated data
 security
 not optimal for
individual/group
 performance
 DBMS cost &
development
Enterprise Databases

Benefits
 meet needs
 data shared
 “mineable”
 consistent view to
customers

Drawbacks
 size & complexity
 security
 cost & support
 development
 standards &
bureaucracy
 distribution &
ownership
Best Database?
Personal?
 Workgroup?
 Department?
 Enterprise?

Best Database?
Personal?
 Workgroup?
 Department?
 Enterprise?
Combination of databases that meets the
needs of individuals, teams,
departments, and the company

Best Database?
To the individual, it’s a personal
database
 To the team, it’s a workgroup database
 To the department, it’s a department
database
 To the CEO, it’s an enterprise database
 (To the DBA, it’s a headache)

Homework #1
Data management recommendation
 High-level, experience based
 “glossy” vendor material
 Show
 alternatives
 strengths/weaknesses of each
 well-reasoned explanation
