1. What is a Database? SECTION 1

2. Database Technology and its Evolution Decades long evolution Early data processing systems Today's systems New technology

3. File-Oriented Systems Early business computer systems Data processing systems Sequential processing Application program

4. Data from a File- Oriented System

5. Random Access Processing Limitations of sequential processing systems Sequential processing leads to additional work Solved by :

6. Limitations of Traditional File Systems Data redundancy Poor data control Inadequate data manipulation capabilities Excessive programming effort

7. Information as a Resource What is an Information System (IS)? A Management Information System (MIS) Data Information

8. A database A database system Database Management System

9. Database Systems Data models Hierarchical model Pointer

10. Files with a Hierarchical Relationship

11. CUSTOMER INVOICE LINE

12. CUSTOMER INVOICE LINE STORE CONTACT

13. A network model CUSTOMER INVOICE LINE STORE CONTACT SALES REP

14. Relational Databases Systems Pointers - strengths and weaknesses E.F. Codd (1970)

15. An Illustration of Problems with Pointers For each customer, identify the manufacturer of the ordered products. CUSTOMER INVOICE LINE MANUFACTURER PRODUCT No physical connection

16. Codd’s proposal Tables Manipulation languages

17. Database Systems: Hardware, Software, Data, and People A complete database systems consists of: 1Hardware 2Software –DBMS –Application software

18. DBMS Data dictionary Data security and integrity

19. Database Data Item User View 2 User View 3 User View 1

20. 3Data 4People

21. Database & Instance Disk Memory (RAM) CPU Typical components of a server

22. Database: The actual database is a collection of tables or files that reside on the disk Memory (RAM) CPU Disk Database Table 1 Table 2 Table 4 Table 3 Table 5 Table n Two main types of database files: Data Metadata

23. Instance: Software running in memory CPU Disk Database Table 1 Table 2 Table 4 Table 3 Table 5 Table n DBMS Instance Memory (RAM)

24. An Instance: Multiple databases CPU Disk DB01 Table 1 Table 2 Table 4 Table 3 Table 5 Table n DBMS Instance DB02 Table 1 Table 2 Table 4 Table 3 Table 5 Table n Memory (RAM)

25. Multiple Instances: Single database CPU Disk Database Table 1 Table 2 Table 4 Table 3 Table 5 Table n DBMS Instance 01 Instance 02 Memory (RAM)

26. Multiple Instances: Single database CPU02 Disk Database Table 1 Table 2 Table 4 Table 3 Table 5 Table n Memory (RAM) Instance 01 Instance 02 CPU01 Memory (RAM) DBMS

29. INSTANCE OASIS Multiple databases