1. 1 A GUIDE TO ORACLE8 CHAPTER 1: Introduction to Client/Server Databases 1

2. 2 Checking Account Data Files Auto Loan Data Files Savings Account Data Files File-Based Approach to Data Processing 1 Checking Account Programs Auto Loan Programs Savings Account Programs Figure 1-1

3. 3 Problems with Data File Approach  Redundant programs  Duplicate data  Inconsistent data 1

4. 4 Database Approach to Data Processing 1 Organizational Database Management System Checking Account Programs Auto Loan Programs Savings Account Programsh Figure 1-2

5. 5 Personal Databases  Single user’s desktop computer  DBMS and Client Database applications are stored on user’s workstation  All files are transmitted across network 1

6. 6 Personal Database Structure 1 File Requests Updated Files Requested Files Network User 1 Client Workstation (DBMS Application & Client DB Applications) 1. Send file requests. 2. Receives files. 3. Filter data from files and/or 4. Add new data to files. Requested Files File Requests Updated Files File Server 1. “Listens” for file requests. 2. Sends and receives files. User 2 Client Workstation (DBMS Application & Client DB Applications) 1. Send file requests. 2. Receives files. 3. Filter data from files and/or 4. Add new data to files. Figure 1-3

7. 7 Client/Server Databases  DBMS process runs on server  Client applications run on user’s workstation  Data requests are transmitted to DBMS  DBMS only returns filtered data 1

8. 8 Client/Server Database Structure 1 Network Database Server (DBMS Process) 1. “Listens” for data requests, new data, and updates. 2. Filters requested data from the database and sends it to client. User 1 Client Workstation (Client DB Application) 1. Send data request. 2. Receive filtered data. or 3. Send data input or update. User 2 Client Workstation (Client DB Application) 1. Send data request. 2. Receive filtered data. or 3. Send data input or update. Filtered Data Data Request. Data Input/Update. Data Request. Data input/update Figure 1-4

9. 9 Other Advantages of Client/Server Databases  Handling server and client failures  Processing transactions  Handling high data volumes  Providing security  Servicing multiple simultaneous users 1

10. 10 The Oracle8 Environment  SQL*Plus  PL/SQL  Developer  Procedure Builder  Query Builder  Form Builder  Report Builder  Graphics Builder  Project Builder  Oracle Application Server (Web pages) 1

11. 11 Overview of Databases  Hierarchical  Parent-to-child relationships  Relationships maintained using pointers  Relational  Data stored in tables  Relationships created through shared key fields 1

12. 12 Hierarchical Database 1 Figure 1-5

13. 13 Relational Database Terms  Table: Matrix with columns and rows  Column: Data category  Also called fields  Row: Contains actual data values  Also called records 1

14. 14 Relational Database With Two Tables 1 Figure 1-6

15. 15 Relational Database Terms  Primary key: Field whose value must be unique for each record  Candidate key: Field that could be used for primary key  Foreign key  Value must be a primary key in another table  Used to create a relationship 1

16. 16 Creating a Relationship With a Foreign Key 1 Figure 1-7

17. 17 Relational Database Terms  Composite key: Primary key created using multiple fields  Surrogate key: Numerical value generated by the database for use as a primary key 1

18. 18 Example of a Composite Primary Key 1 Figure 1-8

19. 19 Case Study Databases  Clearwater Traders  Mail-order clothing and sporting goods retailer  Northwoods University  University registration system 1

20. 20 Clearwater Traders Tables  CUSTOMER  CUST_ORDER  ITEM  INVENTORY  SHIPPING 1  BACKORDER  ORDERLINE  COLOR  ORDERSOURCE

21. 21 Lookup Tables  Lookup table: List of legal values for a field  COLOR  ORDERSOURCE 1

22. 22 Northwoods University Tables  STUDENT  FACULTY  LOCATION  TERM  COURSE 1  COURSE_SECTION  ENROLLMENT