1. Introduction to Databases
Chapter 1
Introduction to Databases

2. Agenda File-based Systems History of Database
Database Management Systems (DBMS)

3. File-based Definition
Program defines and manages it’s own data

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
Limited data modeling
Third generation
Object-relational DBMS
Object-oriented DBMS

6. Database Definition System catalog Data abstraction
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

8. DBMS Environment Hardware Software Data People Procedure
Client-server architecture
Software
dbms, os, network, application
Data
Schema, subschema, table, attribute
People
Data administrator & database administrator
Database designer: logical & physical
Application programmer
End-user: naive & sophisticated
Procedure
Start, stop, log on, log off, back up, recovery

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

10. Limitations of DBMS Complexity Size Cost Software Hardware Conversion
Performance
Vulnerability

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)