Download Chapter 4 of Database Design, Application Development and

Chapter 4
Introduction to Database Development
Outline
Context for database development
 Goals of database development
 Phases of database development
 CASE tools

McGraw-Hill/Irwin
© 2004 The McGraw-Hill Companies, Inc. All rights reserved.
Information System
INPUTS
Loan Applications
OUTPUTS
PROCESSES
ENVIRONMENT
Payments
Student Loan
Processing
System
Delinquency
Notices
ENVIRONMENT
Statements
Cash
Disbursements
Status
Changes
DATABASE
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Traditional Life Cycle
Preliminary
Investigation
Problem Statement,
Feasibility Study
Systems
Analysis
Feedback
System Requirements
Systems
Design
Feedback
Design Specifications
Systems
Implementation
Operational
System
Maintenance
Feedback
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© 2004 The McGraw-Hill Companies, Inc. All rights reserved.
Development Alternatives

Difficulties
– Operational system is produced late
– Rush to begin implementation
– Requirements are difficult to capture

Alternative methodologies
– Spiral approaches
– Rapid application development

Prototypes may reduce risk
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© 2004 The McGraw-Hill Companies, Inc. All rights reserved.
Graphical Models
Explicit or implicit
 Data model
 Process model
 Environment interaction model
 Emphasize data model

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© 2004 The McGraw-Hill Companies, Inc. All rights reserved.
Broad Goals of Database
Development
Develop a common vocabulary
 Define data meaning
 Ensure data quality
 Provide efficient implementation

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© 2004 The McGraw-Hill Companies, Inc. All rights reserved.
Data Quality Measures
Completeness
 Lack of ambiguity
 Timeliness
 Correctness
 Consistency
 Reliability

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© 2004 The McGraw-Hill Companies, Inc. All rights reserved.
Database Development Phases
Data
requirements
Conceptual Data
Modeling
ERD
Logical Database
Design
Tables
Distributed Database
Design
Distribution Schema
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Physical Database
Design
Internal Schema,
Populated DB
© 2004 The McGraw-Hill Companies, Inc. All rights reserved.
Splitting Conceptual Design
Conceptual Data Modeling
Data Requirements
View Design
View ERDs
View Integration
Entity Relationship Diagrams
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© 2004 The McGraw-Hill Companies, Inc. All rights reserved.
Cross Checking Requirements
System
Requirements
Data Requirements
Database
Development
Application Requirements
Cross
Checking
ERDs, Table Design,
...
Application
Development
Process Models,
Interaction Models,
Prototypes
Operational
Applications
Operational
Database
Operational
System
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© 2004 The McGraw-Hill Companies, Inc. All rights reserved.
Design Skills

Soft
– Qualitative
– Degree of subjectivity
– People-oriented

Hard
– Quantitative
– Objective
– Intensive data analysis
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© 2004 The McGraw-Hill Companies, Inc. All rights reserved.
Design Skills in Phases
Data Requirements
Conceptual Data
Modeling
Design Skills
Soft
Entity Relationship
Diagrams
Logical Database
Design
Relational Database
Tables
Distributed
Database Design
Distribution Schema
Physical
Database Design
Internal Schema, Populated Database
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Hard
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Features of CASE Tools
Diagramming
 Documentation
 Analysis
 Prototyping

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Classification of CASE Tools

Front-end vs. Back-end
– Front-end emphasize data modeling and logical
analysis
– Back-end emphasize code generation and physical
design

DBMS dependent vs. DBMS independent
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© 2004 The McGraw-Hill Companies, Inc. All rights reserved.
Commercial CASE Tools
PowerDesigner 9
 Oracle 9i Designer
 Visual Studio .Net Enterprise Architect
 ERWin
 ER/Studio
 Visible Analyst

McGraw-Hill/Irwin
© 2004 The McGraw-Hill Companies, Inc. All rights reserved.
ER Assistant
CASE tool distributed with the textbook
 Customized for this textbook: supports the
ERD notation used in Chapters 5 and 6
 Drawing tool
 Diagram checking
 Easy to use and powerful tool

McGraw-Hill/Irwin
© 2004 The McGraw-Hill Companies, Inc. All rights reserved.
Summary
Background for second part of the course
 Relationship to information systems
development
 Broad goals
 Development phases
 CASE tool features

McGraw-Hill/Irwin
© 2004 The McGraw-Hill Companies, Inc. All rights reserved.