Database Design

Definition

Database design is the design subactivity consisting of the cohesive collection of all tasks involving the design of one or more related databases (or datastores).

Goals

• Produce the design of one or more related databases.
• Ensure that the design fulfills the relevant requirements.
• Ensure that the design conforms to the relevant architecture.

Objectives

• Produce logical database designs.
• Produce physical database designs.
• Ensure that these designs are properly documented.

Examples

Examples of database design include:

• Flat File Design
• Hierarchical Database Design
• Network Database Design
• Object Database Design
• Relational Database Design
• XML Database Design

Preconditions

Databse design may typically begin when the following preconditions hold:

• The initiation phase has started.
• The database team is initially staffed and adequately trained in database design.
• The following documents are largely complete and are relatively stable:
  • Requirements Documents:
    • System Requirements Specification
    • Glossary
    • Domain Model Document
  • Architecture Documents:
    • System Architecture Document
    • Information Architecture Document
    • Software Architecture Document

Completion Criteria

Database design is typically complete when the following postconditions hold:

• The database design document:
  • Is complete.
  • Has passed evaluation.
  • Has been accepted by the customer representative.
  • Been delivered to the customer organization.

Tasks

• Database Team, which performs:
  • Design Reuse
  • Design Prototyping
  • Design Production:
    • Logical Data Model (i.e., Logical Database Schema) Production:
      • Relational Model (e.g., entity relationship attribute (ERA) diagrams and table definitions).
      • Object Model (e.g., class diagrams, class specifications).
      • Hierarchical Model (e.g., hierarchy diagrams).
    • Physical Data Model (i.e., Physical Database Schema) Production:
      • Relational Model (e.g., entity relationship attribute (ERA) diagrams,table definitions, stored procedures, triggers).
      • Object Model (e.g., class diagrams, class specifications).
      • Hierarchical Model (e.g., hierarchy diagrams).
    • Database Facade Design using the following techniques:
      • Access Analysis
      • Data Mapping
  • Design Refactoring using the following techniques:
    • Database Clustering
    • Database Fragmentation
    • Database Indexing
    • Database Normalization (and denormalization)
    • Database Tuning
    • Data Replication
  • Design Documentation

Work Products

• Documents:
  • Database Design Document
  • Data Dictionary
• Models:
  • Data Model (Relational Databases)
  • Document Model (XML Databases)
  • Hierarchy Model (Hierarchical Databases)
  • Object Model (Object Databases)
• Diagrams:
  • Class Diagram
  • Entity Relationship Diagram
  • Hierarchy Diagram

Guidelines

• TBD