Database Design:Course Overview

Course Objectives

Learn Basic database concepts and theories. Basic data modeling principles.

Practice Database design Database implementation skills

Understand How to build database systems

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Course Requirements Grading

Homework Assignments (20%) Final Project (80%) Participation (Extra Credit)

Prerequisites Basic computer skills (e.g., know how to use PC and Web browser) Technical background is not required.

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Course Policy Students are expected to be active participant in class discussions, where

they will ask questions, provide insights, and explore ideas.

This class advocates an open book policy of allowing students to consult textbooks, Internet resources, and classmates when working on assignments to facilitate learning and promote collaboration.

The Honor Code is in effect. With the open book policy, it is especially important to clearly indicate in submitted work any materials used from other sources. Full citation information should be given for such sources.

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Course Resources Homepage

http://kiyang.kmu.ac.kr/gDB/

Required Readings Lecture material and online contents

Supplemental Readings Databases Demystified

by Andrew Oppel, March 2004, McGraw-Hill

Absolute Beginner's Guide to Databases (1st edition)by John Petersen; 2002, Que

Access 2007: The Missing Manualby Matthew MacDonald; 2006, Pogue Press

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Database Overview

Database Intro Data vs. Information

Data is a collection of facts.Information is data processed for knowledge.

Changing data into informationOrganize data so that it can be viewed in a useful form.

• What form will the derived information take?• How will information be extracted?• What data to collect, how & why?

Requirements• Identify context of data• Organize• Summarize

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Data into Information: Identify Context

DataObama, Barack H. 19610804Bush, George H W. 19240612Bush, George W. 19460706Clinton, William J. 19460819Carter, James E. 19241001

ContextLiving presidents, United States, 2011/1/1

• Name (last name, first name middle initial), birthdate (YYYYMMDD)

Class Roster, Database System Course, LIS Department, KMU, Spring 2011• Name (last name, first name middle initial), student ID

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Data into Information: Organize Data

Identify metadataCourse Title: Database SystemCourse Number: 28149-02Credit Hours: 3.0Class Time: Tuesday 9 - 10:15 a.m.

Thursday 10:30 – 11:45 a.m.Semester: Spring 2011Instructor: Yang, Kiduk Department Library and Information ScienceSchool Keimyung University

Identify additional data items.Student Status: Undergraduate SeniorGPA: 3.7Major: MIS

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Data into Information: Summarize

Patterns, Trends & Visualization

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45% LIS

15%CS

15%ACCT

10%IST

15%TCOM

CS = Computer ScienceACCT = AccountingLIS = Library & Information ScienceTCOM = Telecommunication

Enrollment Pie Chart Enrollment over Time

Database Intro Purpose

Store/retrieve/view data efficiently & effectively.

CharacteristicsA collection of organized data related to a particular subject/purpose

• Structured data, security, control

Database management system• data storage, processing, retrieval

User Interface• data entry, search, view/report

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Database: Definitions Database

is collection of related data and its metadata organized in a structured formatfor optimized information management

Database Management System (DBMS)is a software that enables easy creation, access, and modification of databasesfor efficient and effective database management

Database Systemis an integrated system of hardware, software, people, procedures, and datathat define and regulate the collection, storage, management, and use of data within a database environment

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Database Management System

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Database Systems: Design, Implementation, & Management: Rob & Coronel

- manages interaction between end users and database

Database System Environment

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Database Systems: Design, Implementation, & Management: Rob & Coronel

Hardware Software - OS - DBMS - Applications

People

Procedures

Data

Evolution of Data Models

Timeline

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1960s 1970s 1980s 1990s 2000+

File-based

Hierarchical

Network

Relational

Object-oriented

Web-basedEntity-Relationship

Database: Historical Roots Manual File System

to keep track of data used tagged file folders in a filing cabinetorganized according to expected use

• e.g. file per customereasy to create, but hard to

• locate data• aggregate/summarize data

Computerized File Systemto accommodate the data growth and information needmanual file system structures were duplicated in the computerData Processing (DP) specialists wrote customized programs to

• write, delete, update data (i.e. management)• extract and present data in various formats (i.e. report)

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File System: Example

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Database Systems: Design, Implementation, & Management: Rob & Coronel

File System: Weakness Weakness

“Islands of data” in scattered file systems.

ProblemsDuplication

• same data may be stored in multiple filesInconsistency

• same data may be stored by different names in different format Rigidity

• requires customized programming to implement any changes• cannot do ad-hoc queries

ImplicationsWaste of spaceData inaccuraciesHigh overhead of data manipulation and maintenance

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File System: Problem Case

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CUSTOMER file AGENT file SALES file

A_Name (15 char)

Carol Johnson

A_Name (20 char)

Carol T. Johnson

AGENT (20 char)

Carol J. Smith

- inconsistent field name, field size- inconsistent data values - data duplication

Database System vs. File System

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Database Systems: Design, Implementation, & Management: Rob & Coronel

Relational Database Problems with legacy database systems

Required excessive effort to maintain• Data manipulation (programs) too dependent on physical file structure

Hard to manipulate by end-users• No capacity for ad-hoc query (must rely on DB programmers).

Evolution in Data Organization

E. F. Codd’s Relational Model proposal• Separated the notion of physical representation (machine-view)

from logical representation (human-view)• Considered ingenious but computationally impractical in 1970

Relational Database Model• Dominant database model of today• Eliminated pointers and used tables to represent data• Tables

– flexible logical structure for data representation– a series of row/column intersections– related by sharing common entity characteristic(s)

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Relational Database: Example

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Provides a logical “human-level” view of the data and associations among groups of data (i.e., tables)

Customer_ID Customer_Account Agent_ID1224 4556 231225 4558 25

Agent_ID Last_Name First_Name Phone23 Sturm David 334-567825 Long Kyle 556-3421

Customer_ID Last_Name First_Name Phone Account_Balance1224 Vira Dyne 678-9987 1223.951225 Davies Tricia 556-3342 234.25

Entity Relationship Model Peter Chen’s Landmark Paper in 1976

“The Relationship Model: Toward a Unified View of Data”

Graphical representation of entities and their relationships

Entity Relationship (ER) Model

Based on Entity, Attributes & Relationships• Entity is a thing about which data are to be collected and stored

– e.g. EMPLOYEE• Attributes are characteristics of the entity

– e.g. SSN, last name, first name• Relationships describe an associations between entities

– i.e. 1:M, M:N, 1:1

Complements the relational data model concepts• Helps to visualize structure and content of data groups

– entity is mapped to a relational table• Tool for conceptual data modeling (higher level representation)

Represented in an Entity Relationship Diagram (ERD)• Formalizes a way to describe relationships between groups of data

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E-R Diagram: Chen Model

Entity represented by a rectangle with its name

in capital letters.

Relationships represented by an active or passive verb

inside the diamond that connects the related entities.

Connectivities i.e., types of relationship written next to each entity box.

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Database Systems: Design, Implementation, & Management: Rob & Coronel

E-R Diagram: Crow’s Foot Model Entity

represented by a rectangle with its name in capital letters.

Relationships represented by an active or passive

verb that connects the related entities.

Connectivities indicated by symbols next to

entities.• 2 vertical lines for 1• “crow’s foot” for M

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Database Systems: Design, Implementation, & Management: Rob & Coronel