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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 Database Meta-Data Data-Management Data “In” Information “Out” Data End-User Activity: What is It!?!? 1. 2. 3. 4. A Telephone book Organizing the Phone Book in Alphabetical Order Looking up ‘Michael Fudge’ yields the phone number 555-1234 How many ‘Fudges’ are there in the phone book? 1. 2. 3. Employee records (in a file cabinet) Filing a new employee under “W” because their last name is “Williams” The average employee salary is $40,000 Data or Information? Where’s the Data? Where’s the Metadata? Activity: Data or Meta-Data? 1. 2. 3. 4. 5. 6. A Zip Code: 13244 A Zip Code is 5 Characters XXXXX A List of First Names: Tom, Dick, Harry A Picture, Like This One: The Name of the Picture file FrostTrees.jpg When you place an order, the quantity of the item ordered must be a number >0 Something Data can be information: $5 strange and confusing: (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 class Roster? Our LMS, blackboard? MySQL? SU’s SUMMIT Library system? Data or Metadata? Database? DBMS? Activity: Is it a database? Stats on ESPN.com? My email 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 Logical Internal Highly HW/SW Independent Medium HW Ind. SW Dep External Physical Low HW/SW 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 Millions $ DBMS Market Size 9400 9200 9000 8800 8600 8400 8200 8000 7800 9203 8815 8516 8363 Y2002 Y2003 Y2004 Year Source: Gartner Dataquest (2003) Y2005 An employable skill in the future. Source BLS: 2004 THE DATABASE ENVIRONMENT Questions?