4. Limitations of File-based
• Separation and isolation
• Duplication
• Program & data dependence
• Fixed queries
• Proliferation of application programs
5. History of Database Systems
• First generation
– Hierarchical model
• Information Management System (IMS)
– Network model
• Conference on Data System Languages (CODASYL)
• Data Base Task Group (DBTG)
– Limitation
• Complex program for simple query
• Minimum data independence
• No theoretical foundation
• Second generation
– Relational model
• E. R. Codd
• DB2, Oracle
– Limitation
• Limited data modeling
• Third generation
– Object-relational DBMS
– Object-oriented DBMS
6. Database
• Definition
– A collection of self-describing and integrated
data files
• System catalog
– Meta data
– Data dictionary
– Overhead data
• Data abstraction
7. Database Management System Facility
• Data definition language (DDL)
• Data manipulation language (DML)
• Structured query language (SQL)
• Security system
• Integrity system
• Concurrency control system
• Backup & recovery system
• View mechanism
9. Advantages of DBMS
• Control redundancy
• Consistency
• Integrity
• Security
• Concurrency control
• Backup & recovery
• Data standard
• More information
• Data sharing & conflict control
• Productivity & accessibility
• Economy of scale
• Maintenance
11. Points to Remember
• File-based Systems
• History of Database
• Database Management Systems (DBMS)
12. Assignment
• Review Chapter 1
• Read appendix C
• Turn in your group list: (due 9/18/07) before
class starts (1 point for on time roster, 0 for
late one)