1. Introduction to Database Management J.G. Zheng June 22 nd 2005 DB Chapter 1

2. Overview What is database and why database? Functions and components of database systems Advantages and disadvantages to use database

3. Introduction Some database history Database is widely used for businesses, organizations and governments to manage data and information, as well as for personal use

4. Sample Business Data An example of order form

5. Application Centered Approach Past data depended on applications (programs) to define their meanings and structures For example: What does these piece of data mean? 2161710230302BV0602079495 21617-102303-02-BV06-02-079495

6. Data File Approach (Figure 1.1 on page 3)

7. Data File Problems The data file approach is problematic dealing with large quantities of data Redundancy increases input and maintenance efforts wastes space and slows down processing may introduce inconsistencies to the data Not scalable concurrency issue Limited security Size limitations

8. Database Approach Database processing features the separation of data from programs (data independence, or self-described) It provides a centralized management of data Data sharing Data management

9. Database Systems Basic elements of a database system See figure 1.8, 1.9 on page 12, 13

10. Database A database is a self-describing structure that can store information about multiple types of entities (tables), attributes (columns), and relationships (Figure 1.4 on page 7)

11. Relational Database Based on relations Relation is a mathematical concept relation table Data are arranged in 2-dimensional tables (relations) in a relational database More in Chapter 2 …

12. Database Management System DBMS serves as a controller (gatekeeper) for database, managing and controlling database activities reading, updating and deleting data data backup and recovery creating and maintaining tables and other structures controlling concurrency and consistency providing security DBMS uses SQL as command language (chapter 3)

13. Applications/Programs Applications (programs) serve as intermediaries between users and DBMS, to help users perform information processing tasks Functions include: Providing an easy-to-use user interface (menu, form, report) Executing business logic/process (calculation, analysis) …

14. Organizational Database System

15. Popular Products Desktop database system / personal database Microsoft Access Organizational database systems 1 Oracle (Oracle, 39.8% ) DB2 (IBM, 31.3% ) SQL Server (Microsoft, 12.1%) MySQL Most popular database for the web 1 market share data are from IDC 2003 Report

16. Advantages of Database

17. Disadvantages of Database

18. Database Design Design is a process (chapter 4 and 5) Analysis (conceptual design) Data modeling using Entity Relationship Diagram (ER) Design (logical design) Transforming ER to relations (figures on page 8) Real worldERTables

19. Summary Database processing is a centralized way to manage data (data centered) Database processing has great advantages when dealing with large quantities of data Database system consists of user, application, DBMS and database

20. Good Resources A short database history http://math.hws.edu/vaughn/cpsc/343/2003/history.html Largest databases http://www.wintercorp.com