Technology in Action. Alan Evans Kendall Martin Mary Anne Poatsy. Eleventh Edition. Copyright 2015 Pearson Education, Inc.

Transcription

1 Copyright 2015 Pearson Education, Inc. Technology in Action Alan Evans Kendall Martin Mary Anne Poatsy Eleventh Edition

2 Copyright 2015 Pearson Education, Inc. Technology in Action Chapter 9 Behind the Scenes: Databases and Information Systems

3 Copyright 2015 Pearson Education, Inc. 2 Chapter Topics Database Basics Database Building Blocks Database Types Database Functions How Businesses Use Databases Database Warehousing and Storage Business Intelligence Systems Data Mining

4 Copyright 2015 Pearson Education, Inc. Database Basics Database Building Blocks Database Types Database Functions

5 Database Building Blocks A database is a collection of related data, which can be Stored Sorted Organized Queried Databases make data more meaningful and useful Databases turn data into information Copyright 2015 Pearson Education, Inc. 4

6 Database Building Blocks Databases Versus Lists Databases are not needed for managing all types of data Lists are adequate for simple tasks Other applications have tools to create lists Word Excel Copyright 2015 Pearson Education, Inc. 5

7 Database Building Blocks Databases Versus Lists When a list is not sufficient for organizing data Complex information When multiple people need to access information Copyright 2015 Pearson Education, Inc. 6

8 Database Building Blocks Databases Versus Lists Lists can lead to inconsistencies Repetition of data Errors from inconsistently entered or updated data Data redundancy - unnecessary extra copies of data Lists have other problems Copyright 2015 Pearson Education, Inc. 7

9 Database Building Blocks Databases Versus Lists Copyright 2015 Pearson Education, Inc. 8

10 Database Building Blocks Advantages of Using Databases Databases make our lives easier Databases can manage large amounts of data efficiently Databases make information sharing possible Databases promote data integrity Copyright 2015 Pearson Education, Inc. 9

11 Database Building Blocks Advantages of Using Databases Copyright 2015 Pearson Education, Inc. 10

12 Database Building Blocks Disadvantages of Using Databases Disadvantages of databases Can be more time consuming and expensive to set up and administer Care is needed to insure they function as intended Administrator is responsible for designing, constructing, and maintaining databases Copyright 2015 Pearson Education, Inc. 11

13 Database Building Blocks Database Management Systems How databases are created Database management system (DBMS) is designed to capture and analyze data Four main operations of a DBMS Creating databases and entering data Viewing (or browsing) and sorting data Querying (extracting) data Outputting data Copyright 2015 Pearson Education, Inc. 12

14 Database Building Blocks Database Terminology How data is stored in a database All the records representing student information is a table in this database The city column represents one field in this database Julio s contact data is one record Copyright 2015 Pearson Education, Inc. 13

15 Database Building Blocks Planning and Creating the Database How to create a database with a DBMS Describe the data to be captured Data dictionary & Metadata Copyright 2015 Pearson Education, Inc. 14

16 Database Building Blocks Planning and Creating the Database How data tables are created Step 1: Input unique field names Step 2: Define the data type Step 3: Set a maximum field size Step 4: Set a default value if necessary Repeat for each field in the table Copyright 2015 Pearson Education, Inc. 15

17 Database Building Blocks Planning and Creating the Database How to know what fields are needed Careful planning is required Field should describe a unique piece of data Do not combine two pieces of data Allows for better filtering and sorting Fields can be added or deleted Copyright 2015 Pearson Education, Inc. 16

18 Database Building Blocks Planning and Creating the Database Rules for establishing field names Must be unique within a table Do not use spaces Use underscores or CamelCase can be used Use caption field to display spaces Creating a data dictionary will help you plan Copyright 2015 Pearson Education, Inc. 17

19 Database Building Blocks Planning and Creating the Database Determining what type of data can be entered in a field Data type indicates what type of data can be stored in the fields Prevents wrong type of data from being entered Copyright 2015 Pearson Education, Inc. 18

20 Database Building Blocks Planning and Creating the Database Copyright 2015 Pearson Education, Inc. 19

21 Database Building Blocks Planning and Creating the Database Amount of data which can be entered into a field Field size determines maximum number of characters Tailor field size to match maximum length of data Truncated data can result from field size set too small Copyright 2015 Pearson Education, Inc. 20

22 Database Building Blocks Using Primary Keys Having the same values in the same table It is possible for fields to have the same values Each record must have a unique value, the primary key Primary keys make it impossible to duplicate records Copyright 2015 Pearson Education, Inc. 21

23 Database Building Blocks Using Primary Keys A good primary key Must be unique Doesn t have to represent something AutoNumber data type (Microsoft Access) is often used Copyright 2015 Pearson Education, Inc. 22

24 Copyright 2015 Pearson Education, Inc. 23 Database Types Three major types of databases are in use Relational Object-oriented Multidimensional Relational databases have the largest market share Multidimensional databases are growing

25 Database Types Relational Databases Relational database Organizes data in table format Logically groups similar data into a relation (a table that contains related data) Links data between tables through relationships on common keys Copyright 2015 Pearson Education, Inc. 24

26 Database Types Relational Databases Common field in one table (primary key) linked to common field (foreign key) in second table Need to keep data in related tables synchronized Copyright 2015 Pearson Education, Inc. 25

27 Database Types Relational Databases Relational database Referential integrity: Each value in the foreign table has a corresponding value in the primary table Prevents orphan records Copyright 2015 Pearson Education, Inc. 26

28 Database Types Relational Databases Different types of relationships in relational databases One-to-many One-to-one Many-to-many Copyright 2015 Pearson Education, Inc. 27

29 Database Types Object-Oriented Databases Store data in objects rather than tables Contain methods for processing or manipulating data Can store more types of data than relational databases Can access data faster Copyright 2015 Pearson Education, Inc. 28

30 Database Types Object-Oriented Databases Unstructured data include audio clips, video clips, pictures, and extremely large documents Binary large object (BLOB) is unstructured data encoded in binary form Becoming more popular because of variety of data Costly to convert data but can provide many advantages Copyright 2015 Pearson Education, Inc. 29

31 Database Types Multidimensional Databases Stored data can be analyzed from different perspectives (dimensions) Relational database has only two dimensions (fields and records) Multidimensional databases organize in cube format Copyright 2015 Pearson Education, Inc. 30

32 Database Types Multidimensional Databases Data cube Measure attribute: Main type of data that cube is tracking Feature attributes: Describe measure attribute in meaningful ways Copyright 2015 Pearson Education, Inc. 31

33 Database Types Multidimensional Databases Advantages of multidimensional databases Customized to provide information to variety of users Process data faster Critical for larger databases Especially when accessed via the Internet Copyright 2015 Pearson Education, Inc. 32

34 Copyright 2015 Pearson Education, Inc. 33 Database Functions Functions Populate the database by creating records Allow users to extract subsets of data from the database Output the data in a meaningful and presentable format

35 Database Functions Inputting Data How to get data into the database Can be directly keyed into the database Can import from other files Saves time Reduces data error Must match the format of the database exactly Filters are often applied Nonconforming data is flagged Copyright 2015 Pearson Education, Inc. 34

36 Database Functions Inputting Data How to make manual entry into a database more efficient Input forms used to control data input Each field has a label Data is inputted into the blank boxes Existing data can be changed through forms Ensures that correct record is changed Copyright 2015 Pearson Education, Inc. 35

37 Database Functions Inputting Data Copyright 2015 Pearson Education, Inc. 36

38 Database Functions Data Validation Ensuring that only valid data is entered Process of ensuring that data meets specified guidelines Rule is defined in data dictionary Specified in field properties for each field Violations result in error message with suggested action Common validation rules Copyright 2015 Pearson Education, Inc. 37

39 Database Functions Data Validation Copyright 2015 Pearson Education, Inc. 38

40 Database Functions Data Validation Data entered that falls outside the range of acceptable values No value entered in a required field Copyright 2015 Pearson Education, Inc. 39

41 Database Functions Viewing and Sorting Data Viewing the data in a database Displaying all data at one time is an option Many times data is viewed one record at a time Forms display individual records From only one table From related tables Copyright 2015 Pearson Education, Inc. 40

42 Database Functions Viewing and Sorting Data Reordering records in a database Easy to sort data in ascending or descending order Highlight a column Click Ascending or Descending on the Ribbon Copyright 2015 Pearson Education, Inc. 41

43 Database Functions Viewing and Sorting Data View records by browsing Sort records by field name Copyright 2015 Pearson Education, Inc. 42

44 Database Functions Extracting or Querying Data Displaying a subset of data Use a filter or create a query Query language Structured Query Language (SQL) is the most popular Modern systems provide wizards for creating queries Copyright 2015 Pearson Education, Inc. 43

45 Database Functions Extracting or Querying Data Copyright 2015 Pearson Education, Inc. 44

46 Database Functions Outputting Data Retrieving data from of a database Most common output is viewable or printable report Can generate reports from data in tables or from queries Adjustments can be made to the report Copyright 2015 Pearson Education, Inc. 45

47 Copyright 2015 Pearson Education, Inc. 46 Database Functions Outputting Data Transferring data from a database to another software application Exporting: Putting data into format that another application can understand Data can be imported and exported as well as converted to and from other formats

48 Copyright 2015 Pearson Education, Inc. 47 Check Your Understanding 1. What is a database, and why is using one beneficial? A database is a collection of related data that can be stored, sorted, organized, and queried. Many actions we do every day (use an ATM, shop online, make an airplane reservation) generate data that needs to be stored, managed, and used by others. By creating an organized structure for data, databases make data more meaningful and therefore more useful. Databases effectively turn data into information.

49 Copyright 2015 Pearson Education, Inc. 48 Check Your Understanding 2. What do database management systems do? Databases are created and managed using a database management system (DBMS). A DBMS is specially designed application software (such as Oracle Database or Microsoft Access) that interacts with the user, other applications, and the database to capture and analyze data. The four main operations of a DBMS are as follows: 1. Creating databases and entering data 2. Viewing (or browsing) and sorting data 3. Querying (extracting) data 4. Outputting data

50 Copyright 2015 Pearson Education, Inc. 49 Check Your Understanding 3. What components make up a database? Understanding how databases store information requires knowing the unique terminology developed to describe databases. Databases have three main components: 1. Fields: A database stores each category of information in a field. Fields are displayed in columns. Each field is identified by a field name, which is a way of describing the information in the field. 2. Records: A group of related fields is called a record. 3. Tables (Files): A group of related records is called a table (or file). Tables are usually organized by a common subject.

51 Copyright 2015 Pearson Education, Inc. 50 Check Your Understanding 4. What types of databases are there? The three major types of databases currently in use are relational, object-oriented, and multidimensional. Relational databases operate by organizing data into various tables based on logical groupings. In relational databases, a link between tables that defines how the data is related is referred to as a relationship. An object-oriented database stores data in objects rather than in tables. Objects contain not only data but also methods for processing or manipulating that data. A multidimensional database stores data that can be analyzed from different perspectives, called dimensions. This distinguishes it from a relational database, which stores data in tables that have only two dimensions (fields and records).

52 Copyright 2015 Pearson Education, Inc. 51 Check Your Understanding 5. What are the functions of a relational database? How do relational databases organize and manipulate data? Input (populate) data directly by keying in, or by importing from other sources. Input forms control how new data is entered. Data validation rules help prevent improper data from being entered. Data is viewed/displayed through forms showing individual records, or through tables displaying all related records Queries display a subset of data that match certain criteria. Reports used to output data. Data can be aggregated and sorted. Data can be outputted to other applications to be further manipulated.

53 Copyright 2015 Pearson Education, Inc. How Businesses Use Databases Database Warehousing and Storage Business Intelligence Systems Data Mining

54 Copyright 2015 Pearson Education, Inc. 53 Data Warehousing and Storage Problems arise when Organization gets much larger Data is stored in separate databases Benefits of accessing data from all databases are being recognized Data warehouses and data marts are large storage repositories

55 Data Warehousing and Storage Data Warehouses Large-scale collection of data Contains and organizes data in one place Data comes from multiple databases Consolidate information from various systems Present enterprise-wide view of operations Copyright 2015 Pearson Education, Inc. 54

56 Data Warehousing and Storage Data Warehouses Data is organized as in a normal database Data is organized by subject Focus is on one specific aspect of an operation Can contain information from multiple databases Copyright 2015 Pearson Education, Inc. 55

57 Data Warehousing and Storage Data Warehouses Does not capture data from only one time period Populated with data Internal sources External sources Clickstream data Copyright 2015 Pearson Education, Inc. 56

58 Data Warehousing and Storage Data Staging Fitting source data into the warehouse Data must be staged before being entered into a data warehouse Many programs and procedures might be needed to extract and reformat data Nature and complexity of data determines complexity of process Copyright 2015 Pearson Education, Inc. 57

59 Data Warehousing and Storage Data Staging Copyright 2015 Pearson Education, Inc. 58

60 Data Warehousing and Storage Data Marts How to handle smaller amounts of data Data mart: Small slices of data warehouse Analyze related group of data separated from the main body Pertains to single component of business Vital because different data can be extracted and reformatted Can be stored in specialized data marts Copyright 2015 Pearson Education, Inc. 59

61 Copyright 2015 Pearson Education, Inc. 60 Business Intelligence Systems Software-based solution to gather and analyze information Delivers up-to-the-minute data Integral because they store the functional information All perform similar functions

62 Business Intelligence Systems Copyright 2015 Pearson Education, Inc. 61

63 Business Intelligence Systems Office Support Systems What an office support system accomplishes Office support system (OSS) is designed to improve communications and assist employees in accomplishing tasks Copyright 2015 Pearson Education, Inc. 62

64 Business Intelligence Systems Transaction-Processing Systems Keeps track of everyday business activities Early computers hosted TPSs Copyright 2015 Pearson Education, Inc. 63

65 Business Intelligence Systems Transaction-Processing Systems Batch processing Data is accumulated then several transactions are processed at once Appropriate for activities that are not time sensitive Often more efficient Copyright 2015 Pearson Education, Inc. 64

66 Business Intelligence Systems Transaction-Processing Systems When TPS transactions are processed Most transactions are processed in real-time Real-time processing is when the database is updated while the transaction is taking place Online transaction processing (OLTP) ensures that data in the TPS is current Copyright 2015 Pearson Education, Inc. 65

67 Business Intelligence Systems Management Information Systems Management information system (MIS) Provides timely and accurate information Enables managers to make critical decisions Directs outgrowth of TPSs Powerful if organized and outputted in useful form Often included as a feature of TPSs Can generate various reports Copyright 2015 Pearson Education, Inc. 66

68 Business Intelligence Systems Decision Support Systems Decision Support System (DSS) Another type of business intelligence system Designed to help managers develop solutions for specific problems Uses information from databases and data warehouses Users can add own insights and experiences to solution Copyright 2015 Pearson Education, Inc. 67

69 Business Intelligence Systems Decision Support Systems How DSSs get data Copyright 2015 Pearson Education, Inc. 68

70 Business Intelligence Systems Decision Support Systems What function a model management system performs Assists in building management models Analysis tool provides view of a particular business situation Aids in decision making Used to analyze data to create additional models Copyright 2015 Pearson Education, Inc. 69

71 Business Intelligence Systems Decision Support Systems How a knowledge-based system helps in the decision-making process Fuzzy logic enables the interjection of experiential learning into the equation by considering probabilities Enables a system to be more flexible Consider a wider range of possibilities Copyright 2015 Pearson Education, Inc. 70

72 Business Intelligence Systems Enterprise Resource Planning Systems What an Enterprise Resource Planning (ERP) system does Accumulates relevant information Makes information available Uses a common database Copyright 2015 Pearson Education, Inc. 71

73 Copyright 2015 Pearson Education, Inc. 72 Data Mining Data mining Process by which great amounts of data are analyzed and investigated Objective is to spot significant patterns and trends that would not be obvious

74 Copyright 2015 Pearson Education, Inc. 73 Data Mining Why businesses mine their data Understand customers better Effective marketing by concentrating efforts Data is classified, then cluster analysis allows managers to determine trends How businesses mine their data Classification, Estimation, Affinity grouping, Clustering, Description and Visualization

75 Data Mining Copyright 2015 Pearson Education, Inc. 74

76 Copyright 2015 Pearson Education, Inc. 75 Check Your Understanding 6. What are data warehouses and data marts, and how are they used? A data warehouse is a large-scale collection of data that contains and organizes in one place all the data from an organization s multiple databases. Small slices of the data warehouse, each called a data mart, are often created so that companies can analyze a related set of data that are grouped together and separated out from the main body of data in the data warehouse.

77 Check Your Understanding 7. What is a business intelligence system, and what types of business intelligence systems are used by decision makers? An information system is a software-based solution used to gather and analyze information. Databases, data warehouses, and data marts are integral parts of information systems because they store the information that makes information systems functional. All information systems perform similar functions, including acquiring data, processing that data into information, storing the data, and providing the user with a number of output options with which to make the information meaningful and useful. Office Support System, Transaction Processing Systems, Management Information Systems, Decision Support Systems, and Enterprise Resource Planning Systems are types of business intelligence systems. Copyright 2015 Pearson Education, Inc. 76

78 Copyright 2015 Pearson Education, Inc. 77 Check Your Understanding 8. What is data mining, and how does it work? Data mining is the process by which great amounts of data are analyzed and investigated. Data mining enables managers to sift through data in several ways. Each technique produces different information on which managers can then base their decisions. Classification: Before mining, managers define data classes they think will be helpful in spotting trends. Estimation: Estimation enables managers to assign a value to data based on some criterion. Affinity grouping (or association rules): When mining data, managers can determine which data goes together. Clustering: Clustering involves organizing data into similar subgroups, or clusters. It s different from classification in that there are no predefined classes. Description and visualization: Often, the purpose of data mining is to describe data so that managers can interpret it in new and different ways.

79 All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior written permission of the publisher. Printed in the United States of America. Copyright 2015 Pearson Education, Inc