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12 Chapter 12 Data Warehouse & Data Mining Database Systems: Design, Implementation, and Management, Sixth Edition, Rob and Coronel 1 12 In this chapter, you will learn: • How operational data and decision support data differ • What a data warehouse is and how data for it are prepared • What star schemas are and how they are constructed • What steps are required to successfully implement a data warehouse • What data mining is and what role it plays in decision support Database Systems: Design, Implementation, & Management, 6th Edition, Rob & Coronel 2 12 The Need for Data Analysis • Managers must be able to track daily transactions to evaluate how the business is performing • By tapping into the operational database, management can develop strategies to meet organizational goals • Data analysis can provide information about short-term tactical evaluations and strategies Database Systems: Design, Implementation, & Management, 6th Edition, Rob & Coronel 3 12 Solving Business Problems and Adding Value with Data Warehouse-Based Solutions Database Systems: Design, Implementation, & Management, 6th Edition, Rob & Coronel 4 12 Solving Business Problems and Adding Value with Data Warehouse-Based Solutions (continued) Database Systems: Design, Implementation, & Management, 6th Edition, Rob & Coronel 5 12 Decision Support Systems • Methodology (or series of methodologies) designed to extract information from data and to use such information as a basis for decision making • Decision support system (DSS): – Arrangement of computerized tools used to assist managerial decision making within a business – Usually requires extensive data “massaging” to produce information – Used at all levels within an organization – Often tailored to focus on specific business areas – Provides ad hoc query tools to retrieve data and to display data in different formats Database Systems: Design, Implementation, & Management, 6th Edition, Rob & Coronel 6 12 Decision Support Systems (continued) • Composed of four main components: – Data store component • Basically a DSS database – Data extraction and filtering component • Used to extract and validate data taken from operational database and external data sources – End-user query tool • Used to create queries that access database – End-user presentation tool • Used to organize and present data Database Systems: Design, Implementation, & Management, 6th Edition, Rob & Coronel 7 12 Main Components of a Decision Support System (DSS) Database Systems: Design, Implementation, & Management, 6th Edition, Rob & Coronel 8 12 Transforming Operational Data Into Decision Support Data Database Systems: Design, Implementation, & Management, 6th Edition, Rob & Coronel 9 12 Contrasting Operational and DSS Data Characteristics Database Systems: Design, Implementation, & Management, 6th Edition, Rob & Coronel 10 12 Ten-Year Sales History for a Single Department, in Millions of Dollars Database Systems: Design, Implementation, & Management, 6th Edition, Rob & Coronel 11 12 Yearly Sales Summaries, Two Stores and Two Departments per Store, in Millions of Dollars Database Systems: Design, Implementation, & Management, 6th Edition, Rob & Coronel 12 12 The Data Warehouse • Integrated, subject-oriented, time-variant, nonvolatile database that provides support for decision making Database Systems: Design, Implementation, & Management, 6th Edition, Rob & Coronel 13 12 A Comparison of Data Warehouse and Operational Database Characteristics Database Systems: Design, Implementation, & Management, 6th Edition, Rob & Coronel 14 12 Creating a Data Warehouse Database Systems: Design, Implementation, & Management, 6th Edition, Rob & Coronel 15 12 Online Analytical Processing • Advanced data analysis environment that supports decision making, business modeling, and operations research • OLAP systems share four main characteristics: – Use multidimensional data analysis techniques – Provide advanced database support – Provide easy-to-use end-user interfaces – Support client/server architecture Database Systems: Design, Implementation, & Management, 6th Edition, Rob & Coronel 16 12 Operational vs. Multidimensional View of Sales Database Systems: Design, Implementation, & Management, 6th Edition, Rob & Coronel 17 12 Integration of OLAP with a Spreadsheet Program Database Systems: Design, Implementation, & Management, 6th Edition, Rob & Coronel 18 12 OLAP Client/Server Architecture Database Systems: Design, Implementation, & Management, 6th Edition, Rob & Coronel 19 12 OLAP Server Arrangement Database Systems: Design, Implementation, & Management, 6th Edition, Rob & Coronel 20 12 OLAP Server with Multidimensional Data Store Arrangement Database Systems: Design, Implementation, & Management, 6th Edition, Rob & Coronel 21 12 OLAP Server With Local Mini Data Marts Database Systems: Design, Implementation, & Management, 6th Edition, Rob & Coronel 22 12 Bitmap Representation of REGION Values Database Systems: Design, Implementation, & Management, 6th Edition, Rob & Coronel 23 12 Typical ROLAP Client/Server Architecture Database Systems: Design, Implementation, & Management, 6th Edition, Rob & Coronel 24 12 MOLAP Client/Server Architecture Database Systems: Design, Implementation, & Management, 6th Edition, Rob & Coronel 25 12 Relational vs. Multidimensional OLAP Database Systems: Design, Implementation, & Management, 6th Edition, Rob & Coronel 26 12 Star Schemas • Data modeling technique used to map multidimensional decision support data into a relational database • Creates the near equivalent of a multidimensional database schema from the existing relational database • Yield an easily implemented model for multidimensional data analysis, while still preserving the relational structures on which the operational database is built • Has four components: facts, dimensions, attributes, and attribute hierarchies Database Systems: Design, Implementation, & Management, 6th Edition, Rob & Coronel 27 12 Simple Star Schema Database Systems: Design, Implementation, & Management, 6th Edition, Rob & Coronel 28 12 Possible Attributes for Sales Dimensions Database Systems: Design, Implementation, & Management, 6th Edition, Rob & Coronel 29 12 Three-Dimensional View of Sales Database Systems: Design, Implementation, & Management, 6th Edition, Rob & Coronel 30 12 Slice and Dice View of Sales Database Systems: Design, Implementation, & Management, 6th Edition, Rob & Coronel 31 12 Location Attribute Hierarchy Database Systems: Design, Implementation, & Management, 6th Edition, Rob & Coronel 32 12 Attribute Hierarchies In Multidimensional Analysis Database Systems: Design, Implementation, & Management, 6th Edition, Rob & Coronel 33 12 Star Schema for Sales Database Systems: Design, Implementation, & Management, 6th Edition, Rob & Coronel 34 12 Orders Star Schema Database Systems: Design, Implementation, & Management, 6th Edition, Rob & Coronel 35 12 Normalized Dimension tables Database Systems: Design, Implementation, & Management, 6th Edition, Rob & Coronel 36 12 Multiple Fact Tables Database Systems: Design, Implementation, & Management, 6th Edition, Rob & Coronel 37 12 Implementing a Data Warehouse • Numerous constraints: – Available funding – Management’s view of the role played by an IS department and of the extent and depth of the information requirements – Corporate culture • No single formula can describe perfect data warehouse development Database Systems: Design, Implementation, & Management, 6th Edition, Rob & Coronel 38 12 Factors Common to Data Warehousing • Data warehouse is not a static database • Dynamic framework for decision support that is always a work in progress • Data warehouse data cross departmental lines and geographical boundaries • Must satisfy: – Data integration and loading criteria – Data analysis capabilities with acceptable query performance – End-user data analysis needs • Apply database design procedures Database Systems: Design, Implementation, & Management, 6th Edition, Rob & Coronel 39 12 Data Warehouse Implementation Road Map Database Systems: Design, Implementation, & Management, 6th Edition, Rob & Coronel 40 12 Data Mining • Tools that: – analyze data – uncover problems or opportunities hidden in data relationships, – form computer models based on their findings, and then – use the models to predict business behavior • Require minimal end-user intervention Database Systems: Design, Implementation, & Management, 6th Edition, Rob & Coronel 41 12 Extraction of Knowledge From Data Database Systems: Design, Implementation, & Management, 6th Edition, Rob & Coronel 42 12 Data-Mining Phases Database Systems: Design, Implementation, & Management, 6th Edition, Rob & Coronel 43 12 A Sample of Current Data Warehousing and Data-Mining Vendors Database Systems: Design, Implementation, & Management, 6th Edition, Rob & Coronel 44 12 Summary • Data analysis is used to derive and interpret information from data • Decision support is a methodology designed to extract information from data and to use such information as a basis for decision making • Decision support system is an arrangement of computerized tools used to assist managerial decision making within a business • Data warehouse is an integrated, subjectoriented, time-variant, nonvolatile database that provides support for decision making Database Systems: Design, Implementation, & Management, 6th Edition, Rob & Coronel 45 12 Summary (continued) • Online analytical processing is an advanced data analysis environment that supports decision making, business modeling, and operations research • Star schema is a data-modeling technique used to map multidimensional decision support data into a relational database • The implementation of any company-wide information system is subject to conflicting organizational and behavioral factors Database Systems: Design, Implementation, & Management, 6th Edition, Rob & Coronel 46 12 Summary (continued) • Data mining automates analysis of operational data with the intention of finding previously unknown data characteristics, relationships, dependencies, and/or trends • Data warehouse is storage location for decision support data Database Systems: Design, Implementation, & Management, 6th Edition, Rob & Coronel 47