Page 11 - Accounting Information Systems

x Contents

Controlling Access to the Database 400
The Database Management System 400
Three Conceptual Models 401
ELEMENTS OF THE DATABASE ENVIRONMENT 401
Users 401
Database Management System 401
Database Administrator 404
The Physical Database 407
THE RELATIONAL DATABASE MODEL 407
Relational Database Concepts 408
Anomalies, Structural Dependencies, and Data Normalization 412
DESIGNING RELATIONAL DATABASES 419
Identify Entities 419
Construct a Data Model Showing Entity Associations 421
Add Primary Keys and Attributes to the Model 422
Normalize Data Model and Add Foreign Keys 422
Construct the Physical Database 423
Prepare the User Views 424
Global View Integration 427
DATABASES IN A DISTRIBUTED ENVIRONMENT 427
Centralized Databases 428
Distributed Databases 429
SUMMARY 433
APPENDIX 433

Chapter 10 The REA Approach to Database
Modeling 459

THE REA APPROACH 460
The REA Model 460
DEVELOPING AN REA MODEL 462
Differences between ER and REA Diagrams 463
View Modeling: Creating an Individual REA Diagram 463
VIEW INTEGRATION: CREATING AN
ENTERPRISE-WIDE REA MODEL 470
Step 1. Consolidate the Individual Models 470
Step 2. Define Primary Keys, Foreign Keys, and Attributes 475
Step 3. Construct Physical Database and Produce User Views 477
REA and Value Chain Analysis 481
REA Compromises in Practice 482
SUMMARY 482