Database Design

Database Design Process
Database Life Cycle

Key points
Database design must reflect the information system of which the database is a part
Information systems undergo evaluation and revision within a framework known as the Systems
Development Life Cycle (SDLC)
Databases also undergo evaluation and revision within a framework known as the Database Life Cycle (DBLC)
There are two general design strategies exist: top-down vs. bottom-up design centralized vs. decentralized design

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The Information System
Database
Carefully designed and constructed repository of facts Part of an information system

Information System
Provides data collection, storage, and retrieval
Facilitates data transformation
Includes people, procedures, hardware, and software 3

The Information System (Con’t.)
System Analysis
Establishes need and extent of an information system
Refer to Recommended Requirements Gathering Practices

We are NOT DOING A SYSTEM REQ’T ANALYSIS!!

Systems development
Process of creating information system

Database development
Process of database design and implementation
Creation of database models

Implementation
Creating storage structure
Loading data into database
Providing for data management
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Systems Development Life Cycle
System Analysis

Database Lifecycle (DBLC)

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Database Life Cycle (DBLC)
Phase 1
Phase 2
Phase 3
Phase 4

Phase 5

Phase 6
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Database
Organization

Phase 1: Database Initial Study
Phase 1

Purposes

Phase 2

Analyze company situation

Phase 3

Operating environment
Organizational structure

Phase 4
Phase 5

Define problems and constraints
Define objectives
Define scope and boundaries

Phase 6

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Initial Study Activities

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Phase 2: Database Design
Most Critical DBLC phase
Makes sure final product meets requirements
Focus on data requirements
Subphases
I. Create conceptual design
II. DBMS software selection
III. Create logical