Introduction to Database and
Database Management Systems
Discovering Computers Fundamentals, 2010 Edition
Chapter 91
Objectives Overview
Define the term, database, and explain how a database interacts with
data and information
Describe the qualities of valuable information
Discuss the terms character, field, record,
and filedata and information
Describe file maintenance techniques (adding records, modifying
records, deleting records) and validation techniques
Differentiate between a file processing approach
and the database approach
Discovering Computers Fundamentals, 2010 Edition
Chapter 92See Page 351
for Detailed Objectives
Objectives Overview
Discuss the functions common to most
database management systems
Describe characteristics of relational, object-
oriented, and multidimensional
databasesdatabases
Explain how to access Web databases
Discuss the responsibilities of
database analysts and administrators
Discovering Computers Fundamentals, 2010 Edition
Chapter 93See Page 351
for Detailed Objectives
Databases, Data, and Information
Database
• Collection of data organized in a manner
Data
• Collection of unprocessed items
Information
• Processed data
• Documentsin a manner that allows access, retrieval, and use of that data
items
• Text
• Numbers
• Images
• Audio
• Video
• Audio
• Images
• Video
Discovering Computers Fundamentals, 2010 Edition
Chapter 94Page 352
Databases, Data, and Information
Discovering Computers Fundamentals, 2010 Edition
Chapter 95Pages 352 – 353
Figure 9-1
Databases, Data, and Information
• Database software, often called a database
management system (DBMS), allows users to:
Create a computerized Add, modify, and
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Chapter 96Page 352
Create a computerized database
Add, modify, and delete data
Sort and retrieve dataCreate forms and
reports from the data
Databases, Data, and Information
• Data integrity identifies the quality of the data
• Garbage in, garbage out (GIGO) points out the
accuracy of a computer’s output depends on the
accuracy of the inputaccuracy of the input
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Chapter 97Page 353
Databases, Data, and Information
• Valuable information should have the following
characteristics:
Discovering Computers Fundamentals, 2010 Edition
Chapter 98Page 354
AccurateAccurate VerifiableVerifiable TimelyTimely OrganizedOrganized
AccessibleAccessible UsefulUsefulCost-
effectiveCost-
effective
The Hierarchy of Data
• Data is organized in layers
– Files, records, fields, characters
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Chapter 99Page 355
Figure 9-2
The Hierarchy of Data
• A character is one byte
– Numbers, letters, space,
punctuation marks, or
other symbols
• A field is a combination • A field is a combination
of one or more related
characters
– Field name
– Field size
– Data type
Discovering Computers Fundamentals, 2010 Edition
Chapter 910Pages 355 – 356
Figure 9-3
The Hierarchy of Data
• Common data types include:
Text Numeric AutoNumber Currency
Discovering Computers Fundamentals, 2010 Edition
Chapter 911Page 356
Date Memo Yes/No Hyperlink
Object Attachment
The Hierarchy of Data
• A record is a group of related fields
– A primary key uniquely identifies each record
• A data file is a collection of related records
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Chapter 912Page 356
Figure 9-4
Maintaining Data
• File maintenance refers to the procedures that
keep data current
Adding Modifying
Discovering Computers Fundamentals, 2010 Edition
Chapter 913Pages 357 - 358
Adding records
Modifying records
Deleting records
Maintaining Data
• Users add new records to a file when they obtain
new data
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Chapter 914Page 357
Figure 9-5
Maintaining Data
• Users modify a record to correct inaccurate data
or update old data
Discovering Computers Fundamentals, 2010 Edition
Chapter 915Pages 357 - 358
Figure 9-6
Maintaining Data
• When a record no longer is needed, a user deletes
it from a file
Discovering Computers Fundamentals, 2010 Edition
Chapter 916Pages 358 - 359
Figure 10-7
Maintaining Data
• Validation compares data with a set of rules or
values to find out if the data is correct
Alphabetic/Numeric Check
Range check Consistency check
Discovering Computers Fundamentals, 2010 Edition
Chapter 917Pages 359 - 360
CheckRange check Consistency check
Completeness check Check digit Other checks
Click to view Web Link,click Chapter 9, Click Web Link from left navigation, then click Data Validationbelow Chapter 9
File Processing Versus Databases
File processing system
• Each department has its own set of files
• Used for many years
• Each department has its own set of files
• Used for many years
Database approach
• Programs and users share data
• Reduce data redundancy
• Programs and users share data
• Reduce data redundancy
Discovering Computers Fundamentals, 2010 Edition
Chapter 918Pages 361 - 362
• Used for many years
• Have data redundancy
• Isolate data
• Used for many years
• Have data redundancy
• Isolate data
• Reduce data redundancy
• Improve data integrity
• Share data
• Allows easier access
• Reduces development time
• Can be more vulnerable
• Reduce data redundancy
• Improve data integrity
• Share data
• Allows easier access
• Reduces development time
• Can be more vulnerable
File Processing Versus Databases
Discovering Computers Fundamentals, 2010 Edition
Chapter 919Page 362
Figure 9-10
Database Management Systems
Discovering Computers Fundamentals, 2010 Edition
Chapter 920Page 363
Figure 9-11
Click to view Web Link,click Chapter 9, Click Web Link from left navigation, then click MySQLbelow Chapter 9
Database Management Systems
• A data dictionary contains data about each file in
the database and each field in those files
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Chapter 921Page 364
Figure 9-12
Database Management Systems
• A DBMS provides several tools that allow users
and programs to retrieve and maintain data in the
database Query languageQuery language
Discovering Computers Fundamentals, 2010 Edition
Chapter 922Pages 364 - 366
Query by exampleQuery by example
FormForm
Report generatorReport generator
Database Management Systems
• A query language consists of simple, English-like
statements that allow users to specify the data to
display, print, or store
• Query by example (QBE) provides a GUI to assist • Query by example (QBE) provides a GUI to assist
users with retrieving data
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Chapter 923Pages 364 - 366
Database Management Systems
Discovering Computers Fundamentals, 2010 Edition
Chapter 924Page 365
Figure 9-13
Database Management Systems
• A form is a window on the screen that provides
areas for entering or modifying data in a database
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Chapter 925Page 366
Database Management Systems
• A report generator allows users to design a report
on the screen, retrieve data into the report
design, and then display or print the report
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Chapter 926Page 366
Figure 9-15
Database Management Systems
A DBMS provides means to ensure that only authorized users access data at permitted timesdata at permitted times
• Access privileges
• Principle of least privilege
Discovering Computers Fundamentals, 2010 Edition
Chapter 927Page 367
Click to view Web Link,click Chapter 9, Click Web Link from left navigation, then click Data Securitybelow Chapter 9
Database Management Systems
• A DMBS provides a variety of techniques to
restore the database to a usable form in case it is
damaged or destroyed
Discovering Computers Fundamentals, 2010 Edition
Chapter 928Page 367
BackupBackup LogLog
Recovery
utility
Recovery
utility
Continuous
backup
Continuous
backupClick to view Web Link,click Chapter 9, Click Web Link from left navigation, then click Continuous Backup below Chapter 9
Relational, Object-Oriented, and
Multidimensional Databases
• A data model consists of rules and standards that define how the database organizes data
• A relational databasestores data in tables that
Discovering Computers Fundamentals, 2010 Edition
Chapter 929Page 368
Figure 9-17
stores data in tables that consist of rows and columns– Each row has a primary key
– Each column has a unique name
• A relationship is a link within the dataClick to view Web Link,
click Chapter 9, Click Web Link from left navigation, then click Relational Databases below Chapter 9
Relational, Object-Oriented, and
Multidimensional Databases
• Structured Query Language (SQL) is a query
language that allows users to manage, update,
and retrieve data
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Chapter 930Page 369
Figure 9-18
Relational, Object-Oriented, and
Multidimensional Databases
• An object-oriented database (OODB) stores data
in objects
• Object-oriented databases often use Object
Query Language (OQL) to manipulate and retrieve Query Language (OQL) to manipulate and retrieve
data
Discovering Computers Fundamentals, 2010 Edition
Chapter 931Page 369
Click to view Web Link,click Chapter 9, Click Web Link from left navigation, then click Object-Oriented Databases below Chapter 9
Relational, Object-Oriented, and
Multidimensional Databases
• A multidimensional database can store data in more
than two dimensions of data
– Sometimes known as a hypercube
– Can consolidate data much faster than a relational database
• A data warehouse is a huge database that stores and
manages the data required to analyze historical and
current transactions
Discovering Computers Fundamentals, 2010 Edition
Chapter 932Page 370
Click to view Web Link,click Chapter 9, Click Web Link from left navigation, then click Data Warehousesbelow Chapter 9
Web Databases
• Databases on the Web allow you to:
Shop for products or
servicesBuy or sell stocks Search for a job
Discovering Computers Fundamentals, 2010 Edition
Chapter 933Pages 370 - 371
products or services
Buy or sell stocks Search for a job
Make airline reservations
Register for college classes
Check semester grades
Web Databases
Discovering Computers Fundamentals, 2010 Edition
Chapter 934Page 371
Figure 9-19
Database Administration
• It is important to have a carefully designed
database
Discovering Computers Fundamentals, 2010 Edition
Chapter 935Page 371
Figure 9-20
Click to view Web Link,click Chapter 9, Click Web Link from left navigation, then click Database Design Guidelines below Chapter 9
Database Administration
Database analysts and administrators are responsible for managing and coordinating all database activitiesDatabase analysts and administrators are responsible for managing and coordinating all database activities
Database Analyst (DA)Database Administrator (DBA)
Creates and maintains the data Decides on proper field placement, defines data
relationship, and identifies users’ access privileges
Creates and maintains the data dictionary, manages security, monitors performance, and checks backup and recovery
procedures
Discovering Computers Fundamentals, 2010 Edition
Chapter 936Page 371
Database Administration
• Employees should learn
how to use the data in
the database effectively
– Interact with database
– Identify new data for the
database
– Maintain the database
Discovering Computers Fundamentals, 2010 Edition
Chapter 937Page 372
Summary
How data and information are
valuable assets to an organization
Methods for maintaining high-
quality data
Assessing the quality of valuable
informationan organization
quality data information
Advantages of organizing data in
a database
Various types of databases
Roles of the database analysts
and administrators
Discovering Computers Fundamentals, 2010 Edition
Chapter 938Page 372
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