Database Processing

Tenth Edition

Chapter 1

Introduction to Database Processing

David M. Kroenke DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition © 2006 Pearson Prentice Hall 1-1

The Characteristics of Databases

• The purpose of a

database

is to help people track things of interest to them • Data is stored in

tables

, which have rows and columns like a spreadsheet. A database may have multiple tables, where each table stores data about a different thing • Each row in a table stores data about an occurrence or

instance

of the thing of interest • A database stores

data

and

relationships

DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition © 2006 Pearson Prentice Hall 1-2

Data in Tables

DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition © 2006 Pearson Prentice Hall 1-3

The Key Characteristic of Databases: Related Tables

DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition © 2006 Pearson Prentice Hall 1-4

Naming Conventions in this Textbook • •

Table Names

letters: are written with all capital – STUDENT, CLASS, GRADE

Column names

are written with an initial capital letter, and compound names are written with a capital letter on each word: – Term, Section, ClassNumber, StudentName DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition © 2006 Pearson Prentice Hall 1-5

Databases Create Information

• •

Data

= Recorded facts and figures

Information

= data presented in a meaningful context • Databases record data, but they do so in such a way that we can produce information from the data – The data on STUDENTs, CLASSes and GRADEs could produce information about each student’s GPA DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition © 2006 Pearson Prentice Hall 1-6

Database Examples

DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition © 2006 Pearson Prentice Hall 1-7

In the Beginning, There Were File Processing Systems • The first business information systems stored information by grouping similar data into separate files.

DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition © 2006 Pearson Prentice Hall 1-8

A File-Processing System

DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition © 2006 Pearson Prentice Hall 1-9

Problems with File-Processing Systems • Data separated and isolated • Data often duplicated • Application program dependent • Incompatible data files • Difficult to understand DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition © 2006 Pearson Prentice Hall 1-10

Duplication of Data

• When storing the same data in multiple locations, the likelihood of inconsistency is very high.

• What is my real name?

– Table 1: my name is Dan – Table 2: my name is Danielle – Table 3: my name is Daniel – Table 4: my name is Don DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition © 2006 Pearson Prentice Hall 1-11

The Data in a DBMS

• Data is integrated • Data duplication is reduced • Data is program independent • Data is easy to understand DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition © 2006 Pearson Prentice Hall 1-12

Components of a Database System: Microsoft Access

DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition © 2006 Pearson Prentice Hall 1-13

What Is MS Access?

• MS Access is a

DBMS plus an application generator

: – DBMS creates, processes and administers MS Access databases – The application generator includes query, form and report components • The MS Access DBMS engine is called

Jet

, which is not sold as a separate product • MS Access 2000 and later can be used as an application generator for the MS SQL Server DBMS DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition © 2006 Pearson Prentice Hall 1-14

Microsoft Access

•

Microsoft Access

is a low-end product intended for individual users and small workgroups • MS Access tries to hide much of the underlying database technology from the user • A good strategy for beginners, but not for database professionals • NOTE: MS Access is discussed in detail in Appendix A DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition © 2006 Pearson Prentice Hall 1-15

MS Access in Detail

DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition © 2006 Pearson Prentice Hall 1-16

Applications, the DBMS and SQL

• •

Applications

are the computer programs that users work with • The

Database Management System (DBMS)

creates, processes and administers databases

Structured Query Language (SQL)

internationally recognized standard database language that is used by all commercial DBMSs is an DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition © 2006 Pearson Prentice Hall 1-17

Enterprise-Class Database Systems

DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition © 2006 Pearson Prentice Hall 1-18

Prominent DBMS Products

• • Microsoft Access Microsoft SQL Server – New: Microsoft SQL Server Express • • IBM DB2 Oracle Corporation ORACLE • And don’t overlook MySQL DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition © 2006 Pearson Prentice Hall 1-19

DBMS Power vs. Ease of Use

DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition © 2006 Pearson Prentice Hall 1-20

The Database

• A

database

is a self-describing collection of integrated tables • The tables are called

integrated

because they store data about the relationships between the rows of data • A database is called

self-describing

because it stores a description of itself • The self-describing data are called

metadata

, which is data about data DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition © 2006 Pearson Prentice Hall 1-21

A Database System

DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition © 2006 Pearson Prentice Hall 1-22

File Processing DBMS

The Hierarchy of Data

DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition © 2006 Pearson Prentice Hall 1-23

Typical Metadata Tables

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Three Types of Database Design

DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition © 2006 Pearson Prentice Hall 1-25

Database Design from Existing Data DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition © 2006 Pearson Prentice Hall 1-26

Data Import: One or Two Tables?

This is an important decision, and based on a set of rules known as normalization (which is covered in Chapter Three) DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition © 2006 Pearson Prentice Hall 1-27

Database Design from New Systems Development

Entity-Relationship data modeling is covered in Chapter Five, and data model transformations to database designs are covered in Chapter Six DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition © 2006 Pearson Prentice Hall 1-28

Database Design from Database Redesign Database redesign is covered in Chapter Eight, after coverage of SQL in Chapter Seven DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition © 2006 Pearson Prentice Hall 1-29

Database Working Domains

DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition © 2006 Pearson Prentice Hall 1-30

A Brief History of Database Processing DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition © 2006 Pearson Prentice Hall 1-31

The Relational Database Model

• The dominant database model is the

relational database model

– all current major DBMS products are based on it • Created by IBM engineer

E. F. Codd

1970 • It was based on mathematics called

relational algebra

• This text examines and explains the relational database model in DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition © 2006 Pearson Prentice Hall 1-32