MIS380-Chapter 1 Introduction to Database Processing

Four Database Examples

1. Mary Richards Housepainting
   • needs to keep track of her business records
   • single-user database
2. Treble Clef Music
   • needs to keep track of rented musical instruments
   • multi-user database over a LAN
3. State Licensing and Vehicle Registration Bureau
   • needs to keep track of drivers' licenses and auto licenses
   • multi-user database over a WAN
4. Rose Harbor Yacht Sales
   • needs to keep track of sailboats for sale
   • requires a multimedia database
5. Comparison of Database Applications

Relationship of Application Programs and the DBMS

• used to be a well-defined difference (i.e. COBOL & IMS)
• most applications are now integrated into the DBMS

File-Processing Systems (limitations)

• Separated and Isolated Data
• Data Duplication - data integrity
• Application Program Dependency on Data (e.g. Year 2000 crisis)
• Incompatible Files
• The Difficulty of Representing Data in Users' Perspective (not natural)

Database Processing Systems

• Integrated Data - database
• Reduced Data Duplication
• Program/Data Independence
• Easier Representation of the Users' Perspective

Definition of a Database

• A Database is Self-Describing - description is in a data dictionary
• A Database is a Collection of Integerated Records - uses indexes
• A Database is a Model of a Model (model of the users' model = views)

History of Database Processing

• The Organizational Context - designed to overcome limitations of a file-processing system
• The Relational Model
  • developed by E.F. Codd in 1970 using relational algebra
  • data stored in "tables" (rows and columns)
  • may require normalization
• Microcomputer DBMS Products - introduced in 1979 by Ashton-Tate (dBase II)
• Client-Server Database Applications - introduced in late 1980s
• Multimedia and Network Databases
• Distributed Database Processing
• Object-Oriented DBMS (ODBMS) - still emerging