Oracle User Conference Is Data Modeling Dead

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Oracle User ConferenceIs Data Modeling Dead?

• DeVRY University
• March 20, 2006
• Professor Tanya Cannon

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Presentation Agenda

• Introduction to System Development Life Cycle
  (SDLC)
• Process Modeling vs. Data Modeling
• Data Oriented Approach
• Automobile Insurance Application (AIA) - Context
  Data Flow Diagram
• Purpose of Data Modeling
• Normalization Steps
• Normalization Student Example (Physical ERD)
• AIA Data Model Example
• Logical ERD Example
• Physical ERD Example
• Is Data Modeling Dead?
• Open Discussion!

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SDLC Overview

• SDLC Work Breakdown Structure (WBS)

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Why Follow a SDLC?

• The cost of finding errors increase exponentially
  as you go through the life cycle.

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Traditional vs. Modern Approach

• Model Driven Approaches (SAD, IE, OOAD, etc)

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Process Model vs. Data Model

• John Zachman Information System Framework
• (Knowledge is the data oriented approach)

http//members.ozemail.com.au/ieinfo/zachman.htm
WhatisFramework
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Context Data Flow Diagram (System Boundary)
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Purpose of Data Modeling

• Brief Data Modeling Background
• Developed by Boyce Codd (IBM) in 1970
• Considered ingenious but impractical in 1970
• Conceptually simple
• Computers lacked power to implement the
  relational model
• Today, microcomputers can run sophisticated
  relational database software

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Purpose of Data Modeling

• To document the business information requirements
• To identify reuse requirements and opportunities
• To document data requirements based functional
  activity and/or business rules
• To assist in identification of redundant
  processes
• To guide and support consistent data
  administration

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Normalization

• Process for evaluating and correcting table
  structures to minimize data redundancies.
• It helps eliminate data anomalies.
• The three steps of data normalization.

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Normalization

• The three steps of data normalization are
• 1NF - All repeating groups are removed
• 2NF - All Partial dependencies are removed
• 3NF - All Transitive dependencies are removed

• All non-key attributes must depend on the entire
  primary key, and nothing but the primary key, so
  help me CODD.

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Normalization Un-normalized Data
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Normalization 1NF
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Normalization 2NF
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Normalization 3NF
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Normalization Results Summary
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Normalization - Physical ERD
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AIA Data Model Example

• AIA Logical ERD Example
• Normalization Occurred
• (Moving from Logical to Physical Model)
• AIA Physical ERD Example

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AIA - Logical ERD Example
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AIA - Physical ERD Example
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Is Data Modeling Dead?

• Some reasons for the question
• Failure of enterprise data models?
• RAD/Prototyping Techniques?
• Object Oriented Analysis Design?

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Is Data Modeling Dead?

• Open Discussion !!!