McGraw-Hill/Irwin McGraw-Hill/Irwin ©2005 The McGraw-Hill Companies, ©2005 The McGraw-Hill Companies, All rights reserved All rights reserved CHAPTER 3 DATABASES AND DATA WAREHOUSES McGraw-Hill/Irwin ©2005 The McGraw-Hill Companies, All rights reserved OPENING CASE STUDY • Chrysler Spins a Competitive Advantage with Supply Chain Management Software • Chapter 2 – supply chain management is a key business initiative • Chrysler’s SCM is called SPIN, a Web-based system 3-3 OPENING CASE STUDY • Behind SPIN are powerful databases • Databases store a wealth of information – – – – – Inventory Work-in-progress Supplier information Recall notices Customer purchases • This chapter – databases and data warehouses 3-4 STUDENT LEARNING OUTCOMES 1. Describe business intelligence and its role 2. Compare databases and data warehouses by OLTP and OLAP 3. List/describe key characteristics of a relational database 4. Define 5 software components of a DBMS 3-5 STUDENT LEARNING OUTCOMES 5. List/describe key characteristics of a data warehouse 6. Define 4 major types of data-mining tools 7. List key considerations in managing information as a resource 3-6 INTRODUCTION • Organizations need business intelligence • Business intelligence (BI) – knowledge about your customers, competitors, business partners, competitive environment, and internal operations to make effective, important, and strategic business decisions 3-7 INTRODUCTION • IT tools help process information to create business intelligence according to: – OLTP – OLAP 3-8 INTRODUCTION • Online transaction processing (OLTP) – the gathering of input information, processing that information, and updating existing information to reflect the gathered and processed information – Databases support OLTP – Operational database – databases that support OLTP 3-9 INTRODUCTION • Online analytical processing (OLAP) – the manipulation of information to support decision making – Databases can support some OLAP – Data warehouses only support OLAP, not OLTP – Data warehouses are special forms of databases that support decision making 3-10 INTRODUCTION 3-11 THE RELATIONAL DATABASE MODEL • There are many types of databases • The relational database model is the most popular • Relational database – uses a series of logically related two-dimensional tables or files to store information in the form of a database 3-12 Databases Are… • • • • Collections of information Created with logical structures With logical ties within the information With built-in integrity constraints 3-13 Databases – Collections of Information • Databases have many tables • Consider Solomon Enterprises that provides concrete to home and commercial builders. Tables or files include: – – – – – Order Customer Concrete Type Employee Truck 3-14 Databases – Collections of Information 3-15 Databases – Created with Logical Structures • In databases, the row number is irrelevant • Not true in spreadsheet software • In databases, column names are very important. Column names are created in the data dictionary • Data dictionary – contains the logical structure of the information in a database 3-16 Databases – With Logical Ties Within the Information • Logical ties must exist between the tables or files in a database • Logical ties are created with primary and foreign keys • Primary key – field (or group of fields in some cases) that uniquely describes each record • Can you find primary keys in Figure 3.1 on page 129? 3-17 Databases – With Logical Ties Within the Information • Foreign key – primary key of one file that appears in another file • Foreign keys help you create logical ties within the information in a database 3-18 Databases – With Logical Ties Within the Information 3-19 Databases – With Built-In Integrity Constraints • Integrity constraints – rules that help ensure the quality of the information • Examples – – – – Primary keys must be unique Foreign keys must be present Sales price cannot be negative Phone number must have area code 3-20 DATABASE MANAGEMENT SYSTEM TOOLS • Database management system (DBMS) – helps you specify the logical organization for a databases and access and use the information within a database – Word processing software = document – Spreadsheet software = workbook – DBMS software = database 3-21 DATABASE MANAGEMENT SYSTEM TOOLS • 5 software components: 1. 2. 3. 4. 5. DBMS engine Data definition subsystem Data manipulation subsystem Application generation subsystem Data administration subsystem 3-22 DATABASE MANAGEMENT SYSTEM TOOLS 3-23 DBMS Engine • DBMS engine – accepts logical requests from the various other DBMS subsystems, converts them into their physical equivalent, and actually accesses the database and data dictionary as they exist on a storage device • DBMS engine separates the logical from the physical 3-24 DBMS Engine • Physical view – how information is physically arranged, stored, and accessed on some type of storage device • Logical view – how you as a knowledge worker need to arrange and access information • With a database, you only concern yourself with your logical view 3-25 Data Definition Subsystem • Data definition subsystem – helps you create and maintain the data dictionary and define the structure of the files in a database • You must create a data dictionary before entering information into a database • Module J covers this for Microsoft Access 3-26 Data Manipulation Subsystem • Data manipulation subsystem – helps you add, change, and delete information • This is your primary DBMS interface as you work with a database – – – – Views Report generators QBE tools SQL 3-27 Views • View – allows you to see the contents of a database file – – – – Make whatever changes you want Perform simple sorting Query to find the location of information Looks similar to a workbook with no row numbers 3-28 Views 3-29 Report Generators • Report generator – helps you quickly define formats of reports and what information you want to see in a report • You can save report formats and generate reports at any time with up-to-date information 3-30 Report Generators 3-31 Report Generators 3-32 QBE Tools • Query-by-example (QBE) tool – helps you graphically design the answer to a question • “What driver most often delivers concrete to Triple A Homes?” 3-33 QBE Tools 3-34 SQL • Structured query language (SQL) – standardized fourth-generation language found in most DBMSs • Performs the same task as a QBE tool – But uses a sentence structure instead of pointand-click interface • SQL is used mostly by IT people 3-35 Application Generation Subsystem • Application generation subsystem – contains facilities to help you develop transaction-intensive applications – Data entry screen (called forms) – Programming languages • Used mostly by IT specialists 3-36 Data Administration Subsystem • Data administration subsystem – helps you manage the overall database environment – – – – – Backup and recovery Security management Query optimization Concurrency control Change management 3-37 Data Administration Subsystem • Backup and recovery – Periodically back up information – Recover a database if a failure occurs • Security management – Who has access to what information – Who can perform certain tasks (e.g., add, change, or delete) on information 3-38 Data Administration Subsystem • Query optimization – Restructure physical view of information to optimize response times to queries • Concurrency control – What happens if two people makes changes to the same information at the same time? 3-39 Data Administration Subsystem • Change management – What is the effect of structural changes to a database? – What if you add a new column? – What happens if you delete a column? – What happens if you change a column’s attributes? 3-40 DATA WAREHOUSES AND DATA MINING • Data warehouses support OLAP and decision making • Data warehouses do not support OLTP • Data-mining tools are the tools you use to work with a data warehouse – DBMS software = database – Data-mining tools = data warehouse 3-41 What Is a Data Warehouse? • Data warehouse – logical collection of information – gathered from operational databases – used to create business intelligence that supports business analysis activities and decision-making tasks 3-42 What Is a Data Warehouse? 3-43 What Is a Data Warehouse? • • • • • Multidimensional Rows and columns Also layers Many times called hypercubes What are the dimensions in Figure 3.8 on page 142? 3-44 What Are Data-Mining Tools? • Data-mining tools – software tools that you use to query information in a data warehouse – – – – Query-and-reporting tools Intelligence agents Multidimensional analysis tools Statistical tools 3-45 What Are Data-Mining Tools? 3-46 Query-And-Reporting Tools • Query-and-reporting tools – similar to QBE tools, SQL, and report generators in the typical database environment 3-47 Intelligent Agents • Use various artificial intelligence tools such as neural networks and fuzzy logic to form the basis for “information discovery” and building business intelligence • Help you find hidden patterns in information • Chapter 4 focuses more on these 3-48 Multidimensional Analysis Tools • Multidimensional analysis (MDA) tools – slice-and-dice techniques that allow you to view multidimensional information from different perspectives – Bring new layers to the front – Reorganize rows and columns 3-49 Statistical Tools • Help you apply various mathematical models to the information stored in a data warehouse to discover new information – Regression – Analysis of variance – And so on 3-50 Data Marts • Data warehouses can support all of an organization’s information • Data marts have subsets of an organizationwide data warehouse • Data mart – subset of a data warehouse in which only a focused portion of the data warehouse information is kept 3-51 Data Marts 3-52 Data Mining as a Career Opportunity • Knowledge of data mining can be a substantial career opportunity for you – Query and Analysis and Enterprise Analytic Tools (Business Objects) – Business Intelligence and Information Access tools (SAS) – Many in Cognos (the data warehouse leader) – PowerAnalyzer (Informatica) 3-53 Considerations in Using a Data Warehouse • Do you need a data warehouse? – Perhaps database OLAP is sufficient • Do all employees need the entire data warehouse? – If no, build smaller data marts • How up-to-date must the information be? • What data-mining tools do you need? 3-54 MANAGING THE INFORMATION RESOURCE • Information is an organizational resource • Just like people, capital, and equipment • It must be managed effectively 3-55 MANAGING THE INFORMATION RESOURCE • Who should oversee your organization’s information resource? – Chief information officer (CIO) – oversees an organization’s information resource – Data administration – plans for, oversees the development of, and monitors the information resource – Database administration – technical and operational aspects of managing information 3-56 MANAGING THE INFORMATION RESOURCE • Is information ownership a consideration? – If you create information, you “own” it – You will also share it with others – Because you “own” it, you are responsible for its quality 3-57 MANAGING THE INFORMATION RESOURCE • How “clean” must your information be? – Duplicate information (records) must be eliminated – Inaccurate information must be corrected – Information forms the basis of business intelligence – If your business intelligence is bad, you will make poor decisions 3-58 CAN YOU… 1. Describe business intelligence and its role 2. Compare databases and data warehouses by OLTP and OLAP 3. List/describe key characteristics of a relational database 4. Define 5 software components of a DBMS 3-59 CAN YOU… 5. List/describe key characteristics of a data warehouse 6. Define 4 major types of data-mining tools 7. List key considerations in managing information as a resource 3-60 CHAPTER 3 End of Chapter 3 McGraw-Hill/Irwin ©2005 The McGraw-Hill Companies, All rights reserved