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Oracle User ConferenceIs Data Modeling Dead? DeVRY University March 20, 2006 Professor Tanya Cannon
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!
SDLC Overview SDLC – Work Breakdown Structure (WBS)
Why Follow a SDLC? The cost of finding errors increase exponentially as you go through the life cycle.
Traditional vs. Modern Approach Model Driven Approaches (SA&D, IE, OOAD, etc…)
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
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
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
Normalization • Process for evaluating and correcting table structures to minimize data redundancies. • It helps eliminate data anomalies. The three steps of data normalization.
Normalization “All non-key attributes must depend on the entire primary key, and nothing but the primary key, so help me CODD.” 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
AIA – Data Model Example • AIA – Logical ERD Example • Normalization Occurred (Moving from Logical to Physical Model) • AIA – Physical ERD Example
Is Data Modeling Dead? Some reasons for the question: • Failure of enterprise data models? • RAD/Prototyping Techniques? • Object Oriented Analysis & Design?
Is Data Modeling Dead? Open Discussion !!!