1. Chapter 13 Databases and Information Management

2. Chapter 13 Objectives
Explain why data and information are important to an organization
Explain how to use a query language
Identify file maintenance techniques
Understand how Web databases work
Differentiate between the file processing and database approaches
Discuss the responsibilities of the database analysts and administrators
Discuss the advantages of using a database management system (DBMS)
Identify the qualities of valuable information
Describe characteristics of relational and object-oriented databases
Describe the various types of information systems
Next
Understand the concept of a data warehouse
p. 13.2

3. Data and Information How are data and information related? information
Computers process data into information
Data is raw facts; information is data that is organized and meaningful
data
information
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p Fig. 13-1

4. Data and Information What is a database?
Collection of data organized so you can access, retrieve, and use it
Database software allows you to
Create database
Add, change, and delete data
Sort and query database
Database software also is called database management system (DBMS)
Next
p. 13.2

5. Cannot create correct information from incorrect data
Data and Information
What is data integrity?
Degree to which data is correct
When database contains errors, it loses integrity
Garbage in, garbage out
(GIGO)
Cannot create correct information from incorrect data
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p. 13.3

6. The Hierarchy of Data What is a field?
Combination of one or more characters
Smallest unit of data user accesses
Field name uniquely identifies each field
fields
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p Fig. 13-3

7. The Hierarchy of Data What are characteristics of a field? Data type
data types
Text – letters, numbers, or special characters
Data type
Field size
Numeric – numbers only
Currency – dollar and cent amounts or numbers containing decimal values
Date – month, day, year, and sometimes time information
Memo – lengthy text entries
Yes/No – only the values Yes or No
Hyperlink – Web address that links to a document or a Web page
Object – picture, audio, video, or a document created in other applications such as word processing or spreadsheet
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p. 13.5

8. The Hierarchy of Data What is a record?
Group of related fields
field names
maximum characters in Rating field
records
key field Uniquely identifies each record in file
Also called primary key
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p Fig. 13-2

9. The Hierarchy of Data What is a data file?
Collection of related records stored on disk
Each record in file contains same fields
Each field contains different data
Also called a file
Database usually composed of group of related data files
fields
Sample Customer File
records
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p Fig. 13-3

10. Maintaining Data What is file maintenance?
Procedure that keeps data current
Adding records
Changing records
Deleting records
Next
p. 13.6

11. Maintaining Data What is validation?
Validity check analyzes entered data to help ensure it is correct
Click to view Web Link
then click Validity Checks
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p Fig. 13-7

12. Maintaining Data What is a completeness check?
Error message displays stating which required fields are blank
required information
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p Fig. 13-8

13. Maintaining Data What is a check digit?
Number(s) or character(s) appended to or inserted into primary key value
Used to confirm accuracy of primary key value
Initial primary key: 1367
Calculate total of digits:
= 17
Calculate total of digits again:
1 + 7 = 8
Check digit = 8
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Resulting primary key: 13678 p

14. File Processing Versus Databases
What is a file processing system?
Each department or area within organization has own set of files
Records in one file often do not relate to records in any other file
Problem: same customer may have different name or address in each file
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p Fig. 13-9

15. File Processing Versus Databases
What is the database approach?
Many programs and users can share data in database
Secures data so only authorized users can access certain data items
only one customer file in company database
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p Fig

16. File Processing Versus Databases
What are the strengths of the database approach?
Reduced data redundancy
Improved data integrity
Shared data
Reduced development time
Easier reporting
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17. File Processing Versus Databases
How do a database application and a file processing application differ in the way they might store data?
File processing example
Database example
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p Fig

18. Database Management Systems
What is a database management system (DBMS)?
Software that allows you to create, access, and manage a database
Click to view animation
Click to view Web Link
then click Database Management Systems
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p Fig

19. Database Management Systems
What is a data dictionary?
Contains data about each file in database and each field within those files
Click to view Web Link
then click Data Dictionary
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p Fig

20. Database Management Systems
What is a query language?
Simple, English-like statements that allow you to specify data to display, print, or store
query results
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p Fig

21. Database Management Systems
What is a query by example (QBE)?
Program retrieves records that match criteria entered in form fields
query by example screen
query results
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p Fig

22. Database Management Systems
What is a form?
Window on screen that provides areas for entering or changing data in database
E-form is similar, but used on Web
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p. 13. Fig

23. Database Management Systems
What is a report generator?
Generates report without user’s knowledge of programming
Comes with a database
report
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p Fig

24. Database Management Systems
What is data security?
Access privileges
Define activities that specific user or group of users can perform
DBMS provides means to ensure only authorized users can access data with specified privileges
Read-only privileges
User can retrieve data, but cannot change it
Full-update privileges
User can retrieve and change the data
Click to view video
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25. Database Management Systems
What is a log?
Listing of activities that change database contents
For every change, DBMS places three items in log file
before image: a copy of the customer record prior to the change
the actual change of data
after image: a copy of the customer record after the change
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p Fig

26. Database Management Systems
What is a recovery utility?
Rollforward
DBMS uses log to re-enter changes made to database since last save or backup
Also called forward recovery
Uses log file and/or backups to restore database when it is damaged or destroyed
Rollback
DBMS uses log to undo any changes made to database during a certain period of time
Also called backward recovery
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27. Relational, Object-Oriented and Multidimensional Databases
What is a data model?
Relational Databases
Multidimensional Databases
Object-oriented Databases
Object-relational Databases
Every database and DBMS based on specific data model
Composed of rules and standards
Click to view animation
Next
p Fig

28. Relational, Object-Oriented, and Multidimensional Databases
What is a relational database?
Stores data in tables that consist of rows and columns
Each row has primary key
Each column has a unique name
Relational terminology
Click to view Web Link
then click Relational Databases
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p Fig

29. Relational, Object-Oriented, and Multidimensional Databases
What is normalization?
table
column
relationships
row
Process designed to ensure data within relations (tables) contains least amount of duplication
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p Fig

30. Relational, Object-Oriented, and Multidimensional Databases
What is relational algebra?
Projection operation
Retrieves data from columns (fields)
Uses variables and operations to build new relations
Used to manipulate and retrieve data
Selection operation
Retrieves data from certain rows (records)
Join operation
Combines data from two or more tables
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31. Relational, Object-Oriented, and Multidimensional Databases
What is an example of a projection operation?
Extracts data from column (field)
all rows and columns in Movie table
projection operation results
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p Fig

32. Relational, Object-Oriented, and Multidimensional Databases
What is an example of a selection operation?
Extracts data from a row (record)
all rows and columns in Movie table
selection operation results
Next
p Fig

33. Relational, Object-Oriented, and Multidimensional Databases
What is an example of a combined projection and selection operation?
Extracts data from column (field) for certain rows (records)
all rows and columns in Movie table
projection and selection operation results
Next
p Fig

34. Relational, Object-Oriented, and Multidimensional Databases
What is an example of a join operation?
Combines data from two or more tables using a common column
Rental Table
Movie Table
Rental Table and Movie Table joined on Movie ID Column
Next
p Fig

35. Relational, Object-Oriented, and Multidimensional Databases
What is Structured Query Language (SQL)?
Allows you to manage, update, and retrieve data
Uses relational algebra
Has special keywords and rules included in SQL statements
projection operation
Click to view Web Link
then click SQL
join operation
selection operation
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p Fig

36. Relational, Object-Oriented, and Multidimensional Databases
What is an object-oriented database (OODB)?
Object
Item that can contain both data and activities that read or process data
Stores data in objects
Advantages
Can store more types of data
Can access data faster
Object query language (OQL)
Manipulates and retrieves object-oriented and object-relational data
Click to view Web Link
then click Object-Oriented Databases
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37. Relational, Object-Oriented, and Multidimensional Databases
What are examples of applications appropriate for an object-oriented database?
Multimedia databases
Store images, audio clips, and/or video clips
Hypertext databases
Contain text links to other documents
Groupware databases
Store documents such as schedules, calendars, manuals, memos, and reports
Hypermedia databases
Contain text, graphics, video, and sound
Computer-aided design (CAD) databases
Store data about engineering, architectural, and scientific designs
Web databases
Link to e-form on Web page
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38. Relational, Object-Oriented, and Multidimensional Databases
What is a multidimensional database (MDDB)?
Advantage
Can consolidate data much faster than relational database
Stores data in dimensions
Click to view Web Link
then click Multidimensional Databases
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39. Database Administration
What is the role of the database analyst and administrator?
Database analyst (DA)
Focuses on meaning and usage of data
Decides proper placement of fields, defines relationships among data, and identifies users’ access privileges
Database administrator (DBA)
Creates and maintains data dictionary, manages database security, monitors database performance, and checks backup and recovery procedures
Click to view Web Link
then click Database Administrator
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40. Database Administration
What is the role of the employee as a user?
Employee should learn how to utilize data in database
Take part in designing database that will help achieve company’s overall goals
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41. Database Administration
What are guidelines for developing a database?
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p Fig

42. Qualities of Valuable Information
What are the qualities of valuable information?
Accurate
Organized
Verifiable
Accessible
Useful
Timely
Cost-effective
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43. Qualities of Valuable Information
How do managers use information?
Planning
Organizing
Planning
Planning
Organizing
Leading
Controlling
Planning
Organizing
Leading
1. objectives;
strategies;
tactics
2. money; people;
management; structure
3. communication;
instructions;
motivation
4. performance;
measurement;
corrective action
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p Fig

44. Qualities of Valuable Information
What are the levels of users?
Access information necessary to make decisions – a trend called empowering users
Focus on the company’s overall goals and objectives
Access information necessary to make decisions – a trend called empowering users
Involves day-to-day activities within the company
Applies specific programs and plans necessary to meet the stated objectives
Applies specific programs and plans necessary to meet the stated objectives
Access information necessary to make decisions – a trend called empowering users
Involves day-to-day activities within the company
Involves day-to-day activities within the company
Access information necessary to make decisions – a trend called empowering users
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p Fig

45. Types of Information Systems
What is an information system?
Set of hardware, software, data, people, and procedures that work together to produce information
hardware
people
data
procedures
software
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p Fig

46. Types of Information Systems
What are the five categories of information systems?
Office information systems
Decision support systems
Management information systems
Transaction processing systems
Expert systems
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47. Types of Information Systems
What is a management information system (MIS)?
Generates accurate, timely, and organized information
Managers and other users can
Make decisions
Solve problems
Supervise activities
Track progress
Often integrated with transaction processing systems
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48. Types of Information Systems
What is a detailed report?
Lists one record per line
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p Fig

49. Types of Information Systems
What is a summary report?
Consolidates data, so you can review it quickly and easily
Usually has totals, tables, or graphs
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p Fig

50. Types of Information Systems
What is an exception report?
Identifies data outside of normal condition
Conditions, called exception criteria, define normal activity or status range
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p Fig

51. Types of Information Systems
What is a decision support system (DSS)?
Helps managers analyze data and make decisions
One type of DSS is executive information system (EIS)
Click to view Web Link
then click Decision Support Systems
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p Fig

52. Types of Information Systems
What is a data warehouse?
Huge database system that stores and manages data required to analyze historical and current transactions
Click to view Web Link
then click Data Warehouses
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p Fig

53. Types of Information Systems
What are terms associated with a data warehouse?
Distributed database
Data exists in many separate locations throughout network or Internet
Web farming
Process of collecting data from Internet as source for data warehouse
Data mart
Smaller version of data warehouse
Click stream
Collection of every action that users make as they move through Web site
Data mining
Process of finding patterns and relationships among data
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54. Types of Information Systems
What is an expert system?
Knowledge base
Combined subject knowledge and experiences of human experts
Captures and stores knowledge of human experts
Inference rules
Set of logical judgments applied to knowledge base each time user describes situation to expert system
Click to view Web Link
then click Artificial Intelligence
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55. Types of Information Systems
What is an integrated information system?
Five information systems combined in some way
Office information systems
Transaction processing systems
Management information systems
Decision support systems
Expert systems
Integrated information system
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56. Summary of Databases and Information Management
Data and information
The hierarchy of data
Maintaining data
File processing versus databases
Database management systems
Relational, object-oriented, and multidimensional databases
Database administration
Qualities of valuable information
Types of information systems
Chapter 13 Complete