1. ITEC 3220A Using and Designing Database Systems
Instructor: Prof. Z. Yang
Course Website:
Office: TEL 3049

2. Course Objective
Examine databases, trends in database management systems and their application in a wide range of organizational areas
Provide an overview of database processing, both historical and discussion of recent trends in database management
Provide the student with exposure to a range of tools, including a relational DBMS as well as an object-oriented DBMS

3. Textbooks
Database Systems. Design, Implementation, and Management, 11th Edition - Peter Rob & Carlos Coronel

4. Marking Scheme
Final exam (closed book) - 50% Midterm (closed book) - 35% Assignments (2 assignments) - 15%
Lecture notes will be made available at:

5. Schedule Week 1 Database concepts and the relational database model
Week 2 Entity relationship model
Week 3 Normalization
Week 4 SQL
Week 5 SQL + lab
Week 6 Advanced SQL + lab

6. Schedule (Cont’d) Week 7 Midterm Week 8 Database design & case study
Week 9 Transaction management and concurrent control
Week 10 Transaction management and concurrent control (Cont’d) ; Data warehousing
Week 11 Objected-Oriented database
Week 12 Review

7. Database Systems and Data Models
Introduction
Database Systems and Data Models

8. Basic Definition Data: raw facts
Constitute building blocks of information
Information: is produced by processing data and reveals meaning of data
Good, timely, relevant information key to decision making
Good decision making key to organizational survival
Database: shared, integrated computer structure housing:
End user data
Metadata

9. An Example
Converting data to information

10. An Example (Cont’d)
Metadata

11. What is a Database Management System (DBMS)
A collection of programs that manages the database structure and controls access to the data stored in the database
Possible to share data among multiple applications or users
Example: bank and its ATM machines
Makes data management more efficient and effective
End users have better access to more and better-managed data

12. DBMS Manages Interaction

13. File and File System Terminology Data Field Record File Raw Facts
Group of characters with specific meaning
Record
Logically connected fields that describe a person, place, or thing
File
Collection of related records

14. Example

15. Disadvantages of File Processing
Data Dependence
Change in file’s data characteristics requires modification of data access programs
Lengthy development time
Excessive program maintenance
Structural Dependence
Change in file structure requires modification of related programs

16. Example

17. Disadvantages of File Processing (Cont’d)
Data Redundancy
Different and conflicting versions of same data
Results of uncontrolled data redundancy
Data anomalies
Modification
Insertion
Deletion
Data inconsistency
Lack of data integrity

18. Solution: Database Approach
Database consists of logically related data stored in a single repository
Advantages of database approach
Structural and data independence
Minimal data redundancy
Reduces inconsistency, data anomalies
Improves data sharing and data quality
Stores data structures, relationships, and access paths

19. Database vs. File Systems

20. Database System Environment
Hardware: all the system's physical devices
Software
Operating system software
DBMS software
Application programs and utility software
People
Procedures
Data

21. Database Models
Collection of logical constructs used to represent data structure and relationships within the database
Conceptual models: logical nature of data representation
Implementation models: emphasis on how the data are represented in the database

22. Database Models: Historic Overview
Flat files s s
Hierarchical – 1970s s
Network – 1970s s
Relational – 1980s - present
Object-oriented – 1990s - present
Object-relational – 1990s - present
Data warehousing – 1980s - present
Web-enabled – 1990s - present

23. Hierarchical Database Model
Logically represented by an upside down tree
Each parent can have many children.
Each child has only one parent.

24. Hierarchical Database Model (Cont’d)
Advantages
Conceptual simplicity
Database security and integrity
Data independence
Efficiency
Disadvantages
Complex implementation
Difficult to manage and lack of standards
Lacks structural independence
Application programming and use complexity
Implementation limitations

25. Network Database Model
Each record can have multiple parents
Composed of sets
Each set has owner record and member record.
Member may have several owners.

26. Network Database Model (Cont’d)
Advantages
Conceptual simplicity
Handles more relationship types
Data access flexibility
Promotes database integrity
Data independence
Conformance to standards
Disadvantages
System complexity
Lack of structural independence

27. Relational Database Model
Perceived by user as a collection of tables for data storage
Tables are a series of row/column intersections.
Tables related by sharing common entity characteristic(s).

28. Relational Database Model (Cont’d)

29. Relational Database Model (Cont’d)
Schema for the table
Graphical representation
Text description
AGENT(AGENT_CODE, AGENT_LNAME, AGENT_FNAME, AGENT_INITIAL, AGENT_AREACODE, AGETN_PHONE)
AGENT
AGENT_CODE
AGENT_LNAME
AGENT_FNAME
AGENT_INITIAL
AGENT_AREACODE
AGENT_PHONE

30. Relational Database Model (Cont’d)
Advantages
Structural independence
Improved conceptual simplicity
Easier database design, implementation, management, and use
Ad hoc query capability with SQL
Powerful database management system
Disadvantages
Substantial hardware and system software overhead
Poor design and implementation is made easy
May promote “islands of information” problems

31. Object-Oriented Database Model
Objects or abstractions of real-world entities are stored
Attributes describe properties
Collection of similar objects is a class
Methods represent real world actions of classes
Classes are organized in a class hierarchy
Inheritance is ability of object to inherit attributes and methods of classes above it

32. OO Data Model Advantages Disadvantages Adds semantic content
Visual presentation includes semantic content
Database integrity
Both structural and data independence
Disadvantages
Lack of OODM
Complex navigational data access
Steep learning curve
High system overhead slows transactions

33. Costs and Risks of the Database Approach
Up-front costs:
Installation Management Cost and Complexity
Conversion Costs
Ongoing Costs
Requires New, Specialized Personnel
Need for Explicit Backup and Recovery
Organizational Conflict

34. Review
Basic concepts: data, information, database, DBMS, file, conceptual model, implementation model, etc
Why database and its importance, cost and risk
Different database models
definition
advantage
disadvantage

35. The Relational Database Model
Chapter 3
The Relational Database Model

36. In this chapter, you will learn:
Basic components of the relational database model
Entities and their attributes
Relationships among entities
Relational algebra
Relationship in relational database
Data redundancy

37. Basic Definition Entities and Attributes Tables
Entity is a person, place, event, or thing about which data is collected
Attributes are characteristics of the entity
Tables
Holds related entities or entity set
Also called relations
Comprised of rows and columns

38. Table Characteristics
Two-dimensional structure with rows and columns
Rows (tuples) represent single entity
Columns represent attributes
Row/column intersection represents single value
Tables must have an attribute to uniquely identify each row
Column values all have same data format
Each column has range of values called attribute domain
Order of the rows and columns is immaterial to the DBMS

39. Example Tables

40. Terminology for Relational Database
Table-Oriented
Set-oriented
Record-Oriented
Table
Relation
Record type
Row
Tuple
Record
Column
Attribute
Field

41. Key Consists of one or more attributes that determine other attributes
Primary key (PK) is an attribute (or a combination of attributes) that uniquely identifies any given entity (row).
Key’s role is based on determination
If you know the value of attribute A, you can look up (determine) the value of attribute B

42. Keys (Cont’d) Composite key Key attribute Superkey Candidate key
Composed of more than one attribute
Key attribute
Any attribute that is part of a key
Superkey
Any key that uniquely identifies each entity
Candidate key
A superkey without redundancies

43. Keys (Cont’d) Foreign key (FK) Referential integrity Secondary key
An attribute whose values match primary key values in the related table
Referential integrity
FK contains a value that refers to an existing valid tuple (row) in another relation
Secondary key
Key used strictly for data retrieval purposes

44. Simple Relational Database

45. Controlled Redundancy
Makes the relational database work
Tables within the database share common attributes that enable us to link tables together.
Multiple occurrences of values in a table are not redundant when they are required to make the relationship work.
Redundancy is unnecessary duplication of data

46. Integrity Rules

47. Integrity Rules (cont’d)

48. Exercises
Table name: TRUCK
Table name: BASE
Table name: TYPE

49. Exercises (Cont’d)
For each table, identify the primary key and the foreign keys.
Do the tables exhibit entity integrity? Explain
So the tables exhibit referential integrity? Explain
Identify the TRUCK table’s candidate key (s).
For each table, identify a super key and a secondary key