Living in a Digital World
Discovering
Computers 2011
Objectives Overview
Define the term, database, and explain
how a database interacts with data and
information Define the term, database, and explain
how a database interacts with data and
information
Define the term, data integrity, and describe the qualities of valuable
information
Define the term, data integrity, and describe the qualities of valuable
information
Discuss the terms character, field, record,
and file
Discuss the terms character, field, record,
and file
Describe file maintenance techniques and validation techniques
Describe file maintenance techniques and validation techniques
Differentiate between a file processing
approach and the database approach Differentiate between a
file processing
approach and the
database approach
Objectives Overview
Discuss the functions common to most database management
systems
Discuss the functions common to most database management
systems
Describe characteristics of relational, object-
oriented, and multidimensional
databases
Describe characteristics of relational, object-
oriented, and multidimensional
databases
Explain how to access Web databases
Explain how to access Web databases
Identify database design guidelines and discuss
the responsibilities of database analysts and
administrators
Identify database design guidelines and discuss
the responsibilities of database analysts and
administrators
Discovering Computers 2011: Living in a Digital World Chapter 10
See Page 513 3
for Detailed Objectives
Databases, Data, and Information
Database Database
• Collection of data organized in a manner that allows access,
retrieval, and use of that data
• Collection of data organized in a manner that allows access,
retrieval, and use of that data
Data Data
• Collection of unprocessed items
• Text
• Numbers
• Images
• Audio
• Video
• Collection of unprocessed items
• Text
• Numbers
• Images
• Audio
• Video
Information Information
• Processed data
• Documents
• Audio
• Images
• Video
• Processed data
• Documents
• Audio
• Images
• Video
Databases, Data, and Information
Discovering Computers 2011: Living in a Digital World Chapter 10
Pages 514 – 515 5 Figure 10-1
Databases, Data, and Information
• Database software, often called a database management system (DBMS), allows users to:
Create a computerized database
Create a computerized
database Add, modify, and delete data Add, modify, and
delete data
Sort and retrieve data
Sort and retrieve data Create forms and reports from the data
Create 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 input
Discovering Computers 2011: Living in a Digital World Chapter 10
Page 516 7
Click to view Web Link,
click Chapter 10, Click Web Link from left
navigation, then click Data Integrity
below Chapter 10
Databases, Data, and Information
• Valuable information should have the following characteristics:
Accurate
Accurate Verifiable Verifiable Timely Timely Organized Organized
Accessible
Accessible Useful Useful Cost- effective
Cost-
effective
The Hierarchy of Data
• Data is organized in layers
– Files, records, fields, characters
Discovering Computers 2011: Living in a Digital World Chapter 10
Page 517 9 Figure 10-2
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
The Hierarchy of Data
• Common data types include:
Discovering Computers 2011: Living in a Digital World Chapter 10
Page 518 11
Text Text Numeric Numeric AutoNumber AutoNumber Currency Currency
Date Date Memo Memo Yes/No Yes/No Hyperlink Hyperlink
Object
Object Attachment 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
Maintaining Data
• File maintenance refers to the procedures that keep data current
Discovering Computers 2011: Living in a Digital World Chapter 10
Page 520 13
Adding records
Adding records
Modifying records Modifying
records
Deleting records Deleting
records
Maintaining Data
• Users add new records to a file when they obtain
new data
Maintaining Data
• Users modify a record to correct inaccurate data or update old data
Discovering Computers 2011: Living in a Digital World Chapter 10
Page 521 15 Figure 10-6
Maintaining Data
• When a record no longer is needed, a user deletes
it from a file
Maintaining Data
• Validation compares data with a set of rules or values to find out if the data is correct
Discovering Computers 2011: Living in a Digital World Chapter 10
Pages 522 - 524 17
Alphabetic/Numeric check
Alphabetic/Numeric
check Range check Range check Consistency check Consistency check
Completeness check
Completeness check Check digit Check digit Other checks Other checks
Click to view Web Link,
click Chapter 10, Click Web Link from left
navigation, then click Data Validation
below Chapter 10
File Processing Versus Databases
File processing system File processing system
• Each department has its own set of files
• Used for many years
• Have data redundancy
• Isolate data
• Each department has its own set of files
• Used for many years
• Have data redundancy
• Isolate data
Database approach 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
• Programs and users share data
• Reduce data redundancy
• Improve data integrity
• Share data
• Allows easier access
• Reduces development time
• Can be more vulnerable
File Processing Versus Databases
Discovering Computers 2011: Living in a Digital World Chapter 10
Page 525 19 Figure 10-10
Database Management Systems
Click to view Web
Database Management Systems
• A data dictionary contains data about each file in the database and each field in those files
Discovering Computers 2011: Living in a Digital World Chapter 10
Pages 527 – 528 21 Figure 10-12
Database Management Systems
• A DBMS provides several tools that allow users
and programs to retrieve and maintain data in the database Query language Query language
Query by example Query by example
Form Form
Report generator
Report 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 users with retrieving data
Discovering Computers 2011: Living in a Digital World Chapter 10
Page 528 23
Database Management Systems
Database Management Systems
• A form is a window on the screen that provides areas for entering or modifying data in a database
Discovering Computers 2011: Living in a Digital World Chapter 10
Page 530 25 Figure 10-15
Click to view Web Link,
click Chapter 10, Click Web Link from left
navigation, then click E-Form below Chapter 10
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
Database Management Systems
A DBMS provides means to
ensure that only authorized users access data at permitted times
A DBMS provides means to
ensure that only authorized users access data at permitted times
• Access privileges
• Principle of least privilege
Discovering Computers 2011: Living in a Digital World Chapter 10
Page 531 27
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
Backup
Backup Log Log
Recovery utility Recovery
utility
Continuous backup
Continuous
backup
Database Management Systems
Discovering Computers 2011: Living in a Digital World Chapter 10
Page 532 29 Figure 10-17
Relational, Object-Oriented, and Multidimensional Databases
• A data model consists of rules and standards that
define how the database organizes data
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 2011: Living in a Digital World Chapter 10
Page 533 31 Figure 10-20
Relational, Object-Oriented, and Multidimensional Databases
• Structured Query Language (SQL) is a query language that allows users to manage, update, and retrieve data
Click to view Web
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 2011: Living in a Digital World Chapter 10
Page 534 33
Multimedia database Multimedia
database
Groupware database Groupware
database
Computer- aided design
database Computer- aided design
database
Hypertext database Hypertext
database
Relational, Object-Oriented, and
Multidimensional Databases
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 2011: Living in a Digital World Chapter 10
Pages 535 - 536 35
Click to view Web Link,
click Chapter 10, Click Web Link from left
navigation, then click Data Warehouses below Chapter 10
Web Databases
• Databases on the Web allow you to:
Shop for products or
services Shop for products or
services Buy or sell stocks Buy or sell stocks Search for a job Search for a job
Make airline reservations Make airline
reservations Register for college classes
Register for
college classes Check semester grades
Check semester
grades
Web Databases
Discovering Computers 2011: Living in a Digital World Chapter 10
Page 536 37 Figure 10-23
Video: How a Photo Sharing Site
Keeps Its Data
Database Administration
• It is important to have a carefully designed database
Discovering Computers 2011: Living in a Digital World Chapter 10
Page 537 39 Figure 10-24
Click to view Web Link,
click Chapter 10, Click Web Link from left
navigation,
then click Database Design Guidelines below Chapter 10
Database Administration
Database analysts and administrators are responsible for managing and coordinating all database activities Database analysts and administrators are responsible
for managing and coordinating all database activities
Database Analyst (DA) Decides on proper field placement, defines data
relationship, and identifies users’
access privileges Database Analyst (DA) Decides on proper field placement, defines data
relationship, and identifies users’
access privileges
Database Administrator (DBA) Creates and maintains the data
dictionary, manages security, monitors performance, and checks backup and recovery
procedures
Database Administrator (DBA) Creates and maintains the data
dictionary, manages security, monitors performance, and checks backup and recovery
procedures
Click to view Web Link,
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 2011: Living in a Digital World Chapter 10
Page 538 41 Figure 10-25
