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Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall 1 Technology in Action Chapter 11 Behind the Scenes: Databases and Information Systems Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall 2 Chapter Topics • • • • • • • • Databases and their uses Database components Types of databases Database management systems Relational databases Data warehouses and data marts Information systems Data mining Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall 3 What is a database? Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall 4 Non-computer databases • • • • • • • Paper files in a Doctor’s office Phone book Dictionary Cookbook (Multi-media!) Baseball cards (Multi-media!) Day Planner Sports team sign-up sheet Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall 5 Databases Definitions from the book: • Collections of related data • Easily stored, sorted, organized, and queried • Turn data into information -----------------------------------------------------------------------------My simplified definition: • A collection of information organized in a manner that allows for convenient retrieval. Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall 6 My soccer team Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall 7 Their Uniforms Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall 8 The two tables are related… Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall 9 Some DB words… • Everything is stored in a ‘table’ • A ‘record’ is everything about the person (horizontal) • A ‘field’ is a fact about the person (Example: The Address field for ‘Mark’ contains the word ‘London’ • All records have the same fields, just different data stored in those fields. • Fields are picky about what can be stored in them (data types) Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall 10 Life Without Databases: Lists • Often sufficient for simple tasks • Not appropriate for complex information • Multiple lists lead to – Data redundancy – Data inconsistency – Duplicate data – Sorting issues – Incomplete data Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall 11 Databases • Collections of related data • Easily stored, sorted, organized, and queried • Turn data into information Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall 12 Advantages of Using Databases • Store and retrieve large quantities of information • Enable information sharing • Provide data centralization • Promote data integrity • Allow for flexible use of data Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall 13 Disadvantages of Databases • • • • Complex to construct Time consuming Expensive Privacy concerns Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall 14 Database Terminology • Field: A category of information, displayed in columns • Record: A group of related fields Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall 15 Database Terminology (cont.) • Data type: Type of data that can be stored in a field Data Type Used to Store Example of Data Stored in the Field Text Alphabetic or alphanumeric data Numeric Computational Numbers Computational formulas Mirabel CIS110 256, 1.347, $5600 Credit hours x per-credit tuition charges Date Dates in standard date notation 4/15/2014 Memo Long blocks of text Four score and seven years ago our fathers brought forth on this continent a new nation, conceived in liberty, and dedicated to the proposition that all men are created equal. Object Hyperlink Multimedia files or documents MP3 file, AVI file A hyperlink to a Web page on the www.pearsonhighered.com/techinaction Internet Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall 16 Database Terminology (cont.) • Field size: defines the maximum number of characters that a field can hold. • Set field size to the length of the data it contains Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall 17 Database Terminology (cont.) • Table: A group of related records • Primary key: A field value unique to a record Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall 18 Database Types • Relational databases – Organize data in tables – Link tables to each other through their primary keys • Object-oriented databases – Store data in objects – Also store methods for processing data – Handle unstructured data Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall 19 Database Types (cont.) • Multidimensional databases – Store data in multiple dimensions – Organize data in a cube format • Advantages – Can easily be customized – Process data much faster Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall 20 Database Management Systems (DBMS) • • Application software designed to capture and analyze data Four main operations of a DBMS: – – – – Creating databases and entering data Viewing and sorting data Extracting data Outputting data Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall 21 Creating Databases and Entering Data • Create field names – Identify each type of data – Data dictionary (or database schema) Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall 22 Creating Databases and Entering Data (cont.) • Create individual records – Key in – Import – Input form Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall 23 Data Validation • Validation – Process of ensuring that data entered into the database is correct (or at least reasonable) and complete • Validation rules – Range checks – Completeness checks – Consistency checks – Alphabetic/numeric checks Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall 24 Data Validation (cont.) • Example of a completeness check Required field Error message Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall 25 Viewing and Sorting Data • Browse through records • Sort records by field name Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall 26 Extracting or Querying Data • Query – A question or inquiry – Provides records based on criteria – Structured Query Language (SQL) Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall 27 Extracting or Querying Data (cont.) • Modern databases provide wizards to create queries • Simple Query Wizard creates SQL commands behind the scenes • SQL view: Create, modify, or view SQL code created by the wizard Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall 28 Outputting Data • Reports – Viewable or (printable) electronic output – Summary data reports • Export data Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall 29 Relational Database Operations • Relational databases organize data into tables • Relationships are links between tables with related data • Common field(s) need to exist between tables Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall 30 Types of Relationships • One-to-one – For each record in a table, there is only one corresponding record in a related table • One-to-many – Only one instance of a record in one table; many instances in a related table • Many-to-many – Records in one table related to many records in another Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall 31 Relational Database Operations • Normalization of data (recording data once) reduces data redundancy • Foreign key: The primary key of one table is included in another to establish relationships with that other table Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall 32 Data Storage • Data warehouse – Large-scale repository of data – Organizes all the data related to an organization – Data organized by subject Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall 33 Populating Data Warehouses • Source data – Internal sources • Company databases, etc. – External sources • Suppliers, vendors, etc. – Customers or Web site visitors • Clickstream data Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall 34 Data Staging • Three steps: 1. Extract data from source 2. Reformat the data 3. Store the data • Software programs and procedures created to extract the data and reformat it for storage Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall 35 Data Marts • Small slices of data warehouse • Data for a single department or for use by specific employee groups Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall 36 Data Warehouse Process Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall 37 Managing Data: Information Systems • Information systems – Software-based solutions used to gather and analyze information • Functions performed by information systems include – Acquiring data – Processing data into information – Storing data – Providing output options Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall 38 Information Systems Categories • Five categories 1. 2. 3. 4. 5. Office support systems Transaction-processing systems Management information systems Decision support systems Enterprise resource planning (ERP) systems Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall 39 Office Support Systems (OSSs) • • • • Assist employees in day-to-day tasks Improve communications Example: Microsoft Office Include e-mail, word-processing, spreadsheet, database, and presentation programs Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall 40 Transaction-Processing Systems (TPSs) • Keep track of everyday business activities • Batch processing • Real-time processing Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall 41 Management Information Systems (MISs) • Provide timely and accurate information for managers in making business decisions • Detail report – Transactions that occur during a period of time • Summary report – Consolidated detailed data • Exception report – Unusual conditions Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall 42 Decision Support Systems (DSSs) • Help managers develop solutions for specific problems Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall 43 Model Management Systems • Software that assists in building management models in DSSs • Can be built to describe any business situation • Internal and external models • Typically contain financial and statistical analysis tools Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall 44 Knowledge-Based Systems • Expert system: Replicates human experts • Natural language processing (NLP) system: Enables users to communicate with computers using a natural spoken or written language • Artificial intelligence (AI): Branch of computer science that deals with attempting to create computers that think like humans • Support concept of fuzzy logic Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall 45 Enterprise Resource Planning Systems • Integrate multiple data sources • Enable smooth flow of information • Use common database to store and integrate information • Allow information to be used across multiple areas of an enterprise Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall 46 Data Mining • Process by which great amounts of data are analyzed and investigated • Objective is to spot patterns or trends within the data Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall 47 Data Mining Methods • Classification – Define data classes • Estimation – Assign a value to data • Affinity grouping or association rules – Determine which data goes together • Clustering – Organize data into subgroups • Description and visualization – Get a clear picture of what is happening Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall 48 Chapter 11 Summary Questions • What is a database, and why is it beneficial to use databases? Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall 51 Chapter 11 Summary Questions • What components make up a database? Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall 52 Chapter 11 Summary Questions • What types of databases are there? Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall 53 Chapter 11 Summary Questions • What do database management systems do? Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall 54 Chapter 11 Summary Questions • How do relational databases organize and manipulate data? Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall 55 Chapter 11 Summary Questions • What are data warehouses and data marts, and how are they used? Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall 56 Chapter 11 Summary Questions • What is an information system, and what types of information systems are used in business? Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall 57 Chapter 11 Summary Questions • What is data mining, and how does it work? Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall 58 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 © 2012 Pearson Education, Inc. Publishing as Prentice Hall Chapter 11 59