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Your Interactive Guideto the Digital World
Discovering
Computers 2012
Chapter 10
Managing a Database
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Objectives Overview
Define the term,database, and explain
how a database
interacts with data andinformation
Define the term, dataintegrity, and describe
the qualities of valuableinformation
Discuss the termscharacter, field, record,
and file
Describe file
maintenancetechniques andvalidation techniques
Differentiate between a
file processingapproach and thedatabase approach
Discovering Computers 2012: Chapter 102See Page 513
for Detailed Objectives
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Objectives Overview
Discuss the functionscommon to most
database management
systems
Describe characteristicsof relational, object-
oriented, andmultidimensional
databases
Explain how to accessWeb databases
Identify database design
guidelines and discussthe responsibilities ofdatabase analysts and
administrators
Discovering Computers 2012: Chapter 103See Page 513
for Detailed Objectives
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Databases, Data, and Information
Database
Collection of
data organizedin a mannerthat allowsaccess,
retrieval, anduse of thatdata
Data
Collection of
unprocesseditems
Text
Numbers
Images Audio
Video
Information
Processed data
Documents Audio
Images
Video
Discovering Computers 2012: Chapter 104Page 514
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Databases, Data, and Information
Discovering Computers 2012: Chapter 105Pages 514 515
Figure 10-1
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Databases, Data, and Information
Database software,often called a database
management system(DBMS), allows users to:
Discovering Computers 2012: Chapter 106Page 515
Create a computerizeddatabase
Add, modify, anddelete data
Sort and retrieve dataCreate forms and
reports from the data
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Databases, Data, and Information
Data integrity identifies the quality of the data
Garbage in, garbage out (GIGO) points out the
accuracy of a computers output depends on the
accuracy of the input
Discovering Computers 2012: Chapter 107Page 516
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Databases, Data, and Information
Valuable information should have the following
characteristics:
Discovering Computers 2012: Chapter 108Pages 516 - 517
Accurate Verifiable Timely Organized
Accessible UsefulCost-
effective
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The Hierarchy of Data
Data is organized in layers
Files, records, fields, characters
Discovering Computers 2012: Chapter 109Page 517
Figure 10-2
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The Hierarchy of Data
A character is one byte
Numbers, letters, space,
punctuation marks, or
other symbols
A field is a combination
of one or more related
characters
Field name
Field size
Data type
Discovering Computers 2012: Chapter 1010Page 518
Figure 10-3
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The Hierarchy of Data
Common data types include:
Discovering Computers 2012: Chapter 1011Page 518
Text Numeric AutoNumber Currency
Date Memo Yes/No Hyperlink
Object Attachment
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The Hierarchy of Data
Discovering Computers 2012: Chapter 1012Page 519
Figure 10-4
A record is a group of related fields
A primary keyuniquely identifies each record
A data fileis a collection of related records
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Maintaining Data
File maintenancerefers to the procedures that
keep data current
Discovering Computers 2012: Chapter 1013Page 520
Addingrecords
Modifyingrecords
Deletingrecords
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Maintaining Data
Users add new records to a file when they obtain
new data
Discovering Computers 2012: Chapter 1014Page 520
Figure 10-5
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Maintaining Data
Users modify a record to correct inaccurate data
or update old data
Discovering Computers 2012: Chapter 1015Page 521
Figure 10-6
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Maintaining Data
When a record no longer is needed, a user deletes
it from a file
Discovering Computers 2012: Chapter 1016Page 522
Figure 10-7
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Maintaining Data
Validation compares data with a set of rules or
values to find out if the data is correct
Discovering Computers 2012: Chapter 1017Pages 522 - 524
Alphabetic/Numericcheck
Range check Consistency check
Completeness check Check digit Other checks
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File Processing Versus Databases
Discovering Computers 2012: Chapter 1018Pages 524 - 526
File processing system
Each department has its
own set of files Used for many years
Have data redundancy
Isolate data
Database approach
Programs and users share
data Reduce data redundancy
Improve data integrity
Share data
Allows easier access Reduces development time
Can be more vulnerable
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File Processing Versus Databases
Discovering Computers 2012: Chapter 1019Page 525
Figure 10-10
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Database Management Systems
Discovering Computers 2012: Chapter 1020Page 527
Figure 10-11
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Database Management Systems
A data dictionarycontains data about each file in
the database and each field in those files
Discovering Computers 2012: Chapter 1021Pages 527 528
Figure 10-12
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Database Management Systems
A DBMS provides several tools that allow users
and programs to retrieve and maintain data in the
database
Discovering Computers 2012: Chapter 1022Page 528
Query language
Query by example
Form
Report generator
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Database Management Systems
A query languageconsists 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
users with retrieving data
Discovering Computers 2012: Chapter 1023Page 528
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Database Management Systems
Discovering Computers 2012: Chapter 1024Page 529
Figure 10-13
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Database Management Systems
A form is a window on the screen that provides
areas for entering or modifying data in a database
Discovering Computers 2012: Chapter 1025Page 530
Figure 10-15
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Database Management Systems
A report generatorallows users to design a report
on the screen, retrieve data into the report
design, and then display or print the report
Discovering Computers 2012: Chapter 1026Page 531
Figure 10-16
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Database Management Systems
A DBMS provides means to
ensure that only authorized usersaccess data at permitted times
Access privilegesPrinciple of least privilege
Discovering Computers 2012: Chapter 1027Page 531
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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 2012: Chapter 1028Pages 531 - 532
Backup Log
Recovery
utility
Continuousbackup
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Database Management Systems
Discovering Computers 2012: Chapter 1029Page 532
Figure 10-17
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Relational, Object-Oriented, and
Multidimensional Databases
Discovering Computers 2012: Chapter 1030Page 533
Figure 10-18
A data modelconsists of rules and standards that
define how the database organizes data
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Relational, Object-Oriented, and
Multidimensional Databases
A relational database
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 data
Discovering Computers 2012: Chapter 1031Page 533
Figure 10-20
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Relational, Object-Oriented, and
Multidimensional Databases
Structured Query Language(SQL) is a query
language that allows users to manage, update,
and retrieve data
Discovering Computers 2012: Chapter 1032Page 534
Figure 10-21
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Relational, Object-Oriented, and
Multidimensional Databases
An object-oriented database (OODB) stores data
in objects
Examples of applications appropriate for an
object-oriented database include:
Discovering Computers 2012: Chapter 1033Page 534
Multimediadatabase
Groupwaredatabase
Computer-aided design
database
Hypertextdatabase
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Relational, Object-Oriented, and
Multidimensional Databases
Discovering Computers 2012: Chapter 1034Page 535
Figure 10-22
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Relational, Object-Oriented, and
Multidimensional Databases
A multidimensional databasecan 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 2012: Chapter 1035Pages 535 - 536
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Web Databases
Databases on the Web allow you to:
Discovering Computers 2012: Chapter 1036Page 536
Shop for
products orservices
Buy or sell stocks Search for a job
Make airlinereservations
Register forcollege classes
Check semestergrades
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Web Databases
Discovering Computers 2012: Chapter 1037Page 536
Figure 10-23
id h h i i
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Video: How a Photo Sharing Site
Keeps Its Data
Discovering Computers 2012: Chapter 1038
CLICK TO START
http://localhost/var/www/apps/conversion/tmp/scratch_6/10_PhotoStorageOnline.wmvhttp://localhost/var/www/apps/conversion/tmp/scratch_6/10_PhotoStorageOnline.wmvhttp://localhost/var/www/apps/conversion/tmp/scratch_6/10_PhotoStorageOnline.wmv7/30/2019 Lecture on Database
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Database Administration
It is important to have a carefully designed
database
Discovering Computers 2012: Chapter 1039Page 537
Figure 10-24
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Database Administration
Database analysts and administrators are responsiblefor managing and coordinating all database activities
Database Analyst (DA)
Decides on proper fieldplacement, defines data
relationship, and identifiesusers access privileges
Database Administrator (DBA)
Creates and maintains the datadictionary, manages security,monitors performance, and
checks backup and recoveryprocedures
Discovering Computers 2012: Chapter 1040Page 538
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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 2012: Chapter 1041Page 538
Figure 10-25
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Summary
How data andinformation are
valuable assets toan organization
Methods formaintaining high-
quality data
Assessing thequality of valuable
information
Advantages of
organizing data ina database
Various types ofdatabases
Roles of the
database analystsand administrators
Discovering Computers 2012: Chapter 1042Page 539
Chapter 10
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Your Interactive Guideto the Digital World
Discovering
Computers 2012
Chapter 10
Managing a Database