CHAPTER 1 INTRODUCTION TO DATABASES

							      CHAPTER 1

INTRODUCTION TO DATABASES
           Agenda



• FILE-BASED SYSTEMS
• HISTORY OF DATABASE
• DATABASE MANAGEMENT SYSTEMS
  (DBMS)
    FILE-BASED DEFINITION

• PROGRAM DEFINES AND MANAGES
  IT’S OWN DATA
    LIMITATIONS OF FILE-BASED

•   SEPARATION AND ISOLATION
•   DUPLICATION
•   PROGRAM & DATA DEPENDENCE
•   FIXED QUERIES
•   PROLIFERATION OF APPLICATION
    PROGRAMS
    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)
•   SECOND GENERATION
     – RELATIONAL MODEL
         • E. F. CODD
         • DB2, ORACLE
•   THIRD GENERATION
     – EXTENDED RELATIONAL DATA MODEL/OBJECT-RELATIONAL DATA
        MODEL
     – OBJECTED-ORIENTED DATA MODEL
            DATABASE

• DEFINITION
  – A COLLECTION OF SELF-DESCRIBING
    AND INTEGRATED DATA FILES
• SYSTEM CATALOG
  – META DATA
  – DATA DICTIONARY
  – OVERHEAD DATA
• DATA ABSTRACTION
     DATABASE MANAGEMENT
     SYSTEM (DBMS) FACILITIES
•   DATA DEFINITION LANGUAGE (DDL)
•   DATA MANIPULATION LANGUAGE (DML)
•   STRUCTURED QUERY LANGUAGE (SQL)
•   VIEW
•   SECURITY SYSTEM
•   INTEGRITY SYSTEM
•   CONCURRENCY CONTROL SYSTEM
•   BACKUP & RECOVERY SYSTEM
      DBMS ENVIRONMENT
•   HARDWARE
•   SOFTWARE
•   DATA
•   PEOPLE
•   PROCEDURE
       ROLES IN DATABASE
         ENVIRONMENT
• DATA ADMINISTRATOR &
  DATABASE ADMINISTRATOR
 – Administration
• DATABASE DESIGNER
 – Logical & physical
• APPLICATION PROGRAMMER
• END-USER
 – Naive & sophisticated
     ADVANTAGES OF DATABASE
            SYSTEMS
•   CONTROL REDUNDANCY
•   CONSISTENCY
•   INTEGRITY
•   SECURITY
•   CONCURRENCY CONTROL
•   BACKUP & RECOVERY
•   DATA STANDARD
•   MORE INFORMATION
•   DATA SHARING & CONFLICT CONTROL
•   PRODUCTIVITY & ACCESSIBILITY
•   ECONOMY OF SCALE
•   MAINTENANCE
   LIMITATIONS OF DATABASE
           SYSTEMS
• COMPLEXITY
• SIZE
• COST
   – SOFTWARE
   – HARDWARE
   – CONVERSION
• PERFORMANCE
• VULNERABILITY
       Points to Remember



• FILE-BASED SYSTEMS
• HISTORY OF DATABASE
• DATABASE MANAGEMENT SYSTEMS
  (DBMS)
           ASSIGNMENT
• Review Chapter 1
• Read appendix c & chapter 2