THE DATABASE ENVIRONMENT Where is the wisdom we have lost in knowledge? Where is the knowledge we have lost in information. ~ T.S. Eliot ~

Learning Objectives  Concretize the concepts of data, information, data management and metadata  Explain what a database is and why databases are important  Describe a database management system  Differentiate between the DBMS and a database  Describe the different data models and abstraction layers  Explain the similarities and differences among DBMS products  Explain DBMS history and modern uses  Describe how data is physically stored in primary and secondary storage

Before we begin…What’s… Data? Information? Data Management? Metadata? Query?

Elements of a Database Meta-Data Data Database Data-Management Data “In” Information “Out” End-User

Activity: What is It!?!? 1. A Telephone book 2. Organizing the Phone Book in Alphabetical Order 3. Looking up ‘Michael Fudge’ yields the phone number How many ‘Fudges’ are there in the phone book? 1. Employee records (in a file cabinet) 2. Filing a new employee under “W” because their last name is “Williams” 3. The average employee salary is $40,000

Data or Information?

Where’s the Data? Where’s the Metadata?

Activity: Data or Meta-Data? 1. A Zip Code: A Zip Code is 5 Characters XXXXX 3. A List of First Names: Tom, Dick, Harry 4. A Picture, Like This One: 5. The Name of the Picture file FrostTrees.jpg 6. When you place an order, the quantity of the item ordered must be a number >0

Something strange and confusing:  Data can be information:  $5 (the amount of money in my wallet)  Information can be data:  I calculate student final grades, then place them on a form sent to the registrar’s office.  Metadata can be data:  The names of MP3 files in your personal collection. Actually it’s all about context!

What is it, part duex! Database Database Management System

Database or DBMS?  Microsoft Access?  Our LMS, blackboard?  MySQL?  SU’s SUMMIT Library system?

Data or Metadata? Database? DBMS?

Activity: Is it a database?  Stats on ESPN.com?  My address?  Medical records in a filing cabinet?  A weblog like slashdot.org?  Amazon.com product catalog?  This course syllabus?  All the syllabi on campus?  Your MP3 collection?

Data Models: Abstraction Levels Conceptual Internal External Physical Logical Highly Abstract Hardware and Software Independent Somewhat Abstract Hardware Independent Software Dependent Not Abstract (Concrete) Hardware and Software Dependent

Elements of the DBMS Approach  Enterprise Data Model  Graphical model showing high-level entities and relationships for the organization  Relational Databases  Database technology involving tables (relations) representing entities and primary/foreign keys representing relationships  Use of Internet Technology  Networks and telecommunications, distributed databases, client-server and 3-tier architectures  Database Applications  Application programs used to perform database activities CRUD for database users

Evolution of DBMSs

DBMS Market Share Source: Gartner Dataquest

DBMS Market Size Source: Gartner Dataquest (2003)

An employable skill in the future. Source BLS: 2004

THE DATABASE ENVIRONMENT Questions?