6商业智能的基础：数据和信息管理.ppt

6.16Chapter Foundations of Foundations of Business Intelligence:Business Intelligence:Databases and Databases and Information Information ManagementManagement6.2LEARNING OBJECTIVESManagement Information SystemsManagement Information SystemsChapter 6 Foundations of Business Intelligence:Databases Chapter 6 Foundations of Business Intelligence:Databases and Information Managementand Information ManagementDescribe how the problems of managing data resources in a traditional file environment are solved by a database management systemDescribe the capabilities and value of a database management systemApply important database design principlesEvaluate tools and technologies for accessing information from databases to improve business performance and decision makingAssess the role of information policy,data administration,and data quality assurance in the management of firms data resources6.3Can HP Mine Success from an Enterprise Data Warehouse?Problem:HPs numerous systems unable to deliver the information needed for a complete picture of business operations,lack of data consistencySolutions:Build a data warehouse with a single global enterprise-wide database;replacing 17 database technologies and 14,000 databases in useCreated consistent data models for all enterprise data and proprietary platformDemonstrates importance of database management in creating timely,accurate data and reportsIllustrates need to standardize how data from disparate sources are stored,organized,and managedManagement Information SystemsManagement Information SystemsChapter 6 Foundations of Business Intelligence:Databases Chapter 6 Foundations of Business Intelligence:Databases and Information Managementand Information Management6.4Organizing Data in a Traditional File EnvironmentFile organization conceptsComputer system organizes data in a hierarchyField:Group of characters as word(s)or numberRecord:Group of related fieldsFile:Group of records of same type Database:Group of related filesRecord:Describes an entityEntity:Person,place,thing on which we store informationAttribute:Each characteristic,or quality,describing entityE.g.,Attributes Date or Grade belong to entity COURSEManagement Information SystemsManagement Information SystemsChapter 6 Foundations of Business Intelligence:Databases Chapter 6 Foundations of Business Intelligence:Databases and Information Managementand Information Management6.5The Data HierarchyThe Data HierarchyFigure 6-1A computer system organizes data in a hierarchy that starts with the bit,which represents either a 0 or a 1.Bits can be grouped to form a byte to represent one character,number,or symbol.Bytes can be grouped to form a field,and related fields can be grouped to form a record.Related records can be collected to form a file,and related files can be organized into a database.Management Information SystemsManagement Information SystemsChapter 6 Foundations of Business Intelligence:Databases Chapter 6 Foundations of Business Intelligence:Databases and Information Managementand Information ManagementOrganizing Data in a Traditional File Environment6.6Problems with the traditional file environment(files maintained separately by different departments)Data redundancy and inconsistencyData redundancy:Presence of duplicate data in multiple filesData inconsistency:Same attribute has different valuesProgram-data dependence:When changes in program requires changes to data accessed by programLack of flexibilityPoor securityLack of data sharing and availabilityManagement Information SystemsManagement Information SystemsChapter 6 Foundations of Business Intelligence:Databases Chapter 6 Foundations of Business Intelligence:Databases and Information Managementand Information ManagementOrganizing Data in a Traditional File Environment6.7Traditional File ProcessingTraditional File ProcessingFigure 6-2The use of a traditional approach to file processing encourages each functional area in a corporation to develop specialized applications and files.Each application requires a unique data file that is likely to be a subset of the master file.These subsets of the master file lead to data redundancy and inconsistency,processing inflexibility,and wasted storage resources.Management Information SystemsManagement Information SystemsChapter 6 Foundations of Business Intelligence:Databases Chapter 6 Foundations of Business Intelligence:Databases and Information Managementand Information ManagementOrganizing Data in a Traditional File Environment6.8DatabaseCollection of data organized to serve many applications by centralizing data and controlling redundant dataDatabase management systemInterfaces between application programs and physical data filesSeparates logical and physical views of dataSolves problems of traditional file environmentControls redundancyEliminates inconsistencyUncouples programs and dataEnables organization to central manage data and data securityThe Database Approach to Data ManagementManagement Information SystemsManagement Information SystemsChapter 6 Foundations of Business Intelligence:Databases Chapter 6 Foundations of Business Intelligence:Databases and Information Managementand Information Management6.9Management Information SystemsManagement Information SystemsChapter 6 Foundations of Business Intelligence:Databases Chapter 6 Foundations of Business Intelligence:Databases and Information Managementand Information ManagementFigure 6-3A single human resources database provides many different views of data,depending on the information requirements of the user.Illustrated here are two possible views,one of interest to a benefits specialist and one of interest to a member of the companys payroll department.Human Resources Database with Multiple ViewsHuman Resources Database with Multiple ViewsThe Database Approach to Data Management6.10Relational DBMSRepresent data as two-dimensional tables called relations or filesEach table contains data on entity and attributesTable:grid of columns and rowsRows(tuples):Records for different entitiesFields(columns):Represents attribute for entityKey field:Field used to uniquely identify each recordPrimary key:Field in table used for key fieldsForeign key:Primary key used in second table as look-up field to identify records from original tableManagement Information SystemsManagement Information SystemsChapter 6 Foundations of Business Intelligence:Databases Chapter 6 Foundations of Business Intelligence:Databases and Information Managementand Information ManagementThe Database Approach to Data Management6.11Management Information SystemsManagement Information SystemsChapter 6 Foundations of Business Intelligence:Databases Chapter 6 Foundations of Business Intelligence:Databases and Information Managementand Information ManagementFigure 6-4AA relational database organizes data in the form of two-dimensional tables.Illustrated here are tables for the entities SUPPLIER and PART showing how they represent each entity and its attributes.Supplier_Number is a primary key for the SUPPLIER table and a foreign key for the PART table.Relational Database TablesRelational Database TablesThe Database Approach to Data Management6.12Management Information SystemsManagement Information SystemsChapter 6 Foundations of Business Intelligence:Databases Chapter 6 Foundations of Business Intelligence:Databases and Information Managementand Information ManagementFigure 6-4BRelational Database Tables(cont.)Relational Database Tables(cont.)The Database Approach to Data Management6.13Operations of a Relational DBMSThree basic operations used to develop useful sets of dataSELECT:Creates subset of data of all records that meet stated criteriaJOIN:Combines relational tables to provide user with more information than available in individual tablesPROJECT:Creates subset of columns in table,creating tables with only the information specifiedManagement Information SystemsManagement Information SystemsChapter 6 Foundations of Business Intelligence:Databases Chapter 6 Foundations of Business Intelligence:Databases and Information Managementand Information ManagementThe Database Approach to Data Management6.14Management Information SystemsManagement Information SystemsChapter 6 Foundations of Business Intelligence:Databases Chapter 6 Foundations of Business Intelligence:Databases and Information Managementand Information ManagementFigure 6-5The select,project,and join operations enable data from two different tables to be combined and only selected attributes to be displayed.The Three Basic Operations of a Relational DBMSThe Three Basic Operations of a Relational DBMSThe Database Approach to Data Management6.15Object-Oriented DBMS(OODBMS)Stores data and procedures as objectsCapable of managing graphics,multimedia,Java appletsRelatively slow compared with relational DBMS for processing large numbers of transactionsHybrid object-relational DBMS:Provide capabilities of both OODBMS and relational DBMSManagement Information SystemsManagement Information SystemsChapter 6 Foundations of Business Intelligence:Databases Chapter 6 Foundations of Business Intelligence:Databases and Information Managementand Information ManagementThe Database Approach to Data Management6.16Capabilities of Database Management SystemsData definition capability:Specifies structure of database content,used to create tables and define characteristics of fieldsData dictionary:Automated or manual file storing definitions of data elements and their characteristicsData manipulation language:Used to add,change,delete,retrieve data from database Structured Query Language(SQL)Microsoft Access user tools for generation SQLMany DBMS have report generation capabilities for creating polished reports(Crystal Reports)Management Information SystemsManagement Information SystemsChapter 6 Foundations of Business Intelligence:Databases Chapter 6 Foundations of Business Intelligence:Databases and Information Managementand Information ManagementThe Database Approach to Data Management6.17Management Information SystemsManagement Information SystemsChapter 6 Foundations of Business Intelligence:Databases Chapter 6 Foundations of Business Intelligence:Databases and Information Managementand Information ManagementFigure 6-6Microsoft Access has a rudimentary data dictionary capability that displays information about the size,format,and other characteristics of each field in a database.Displayed here is the information maintained in the SUPPLIER table.The small key icon to the left of Supplier_Number indicates that it is a key field.Microsoft Access Data Dictionary FeaturesMicrosoft Access Data Dictionary FeaturesThe Database Approach to Data Management6.18Management Information SystemsManagement Information SystemsChapter 6 Foundations of Business Intelligence:Databases Chapter 6 Foundations of Business Intelligence:Databases and Information Managementand Information ManagementFigure 6-7Illustrated here are the SQL statements for a query to select suppliers for parts 137 or 150.They produce a list with the same results as Figure 6-5.Example of an SQL QueryExample of an SQL QueryThe Database Approach to Data Management6.19Management Information SystemsManagement Information SystemsChapter 6 Foundations of Business Intelligence:Databases Chapter 6 Foundations of Business Intelligence:Databases and Information Managementand Information ManagementFigure 6-8Illustrated here is how the query in Figure 6-7 would be constructed using query-building tools in the Access Query Design View.It shows the tables,fields,and selection criteria used for the query.An Access QueryAn Access QueryThe Database Approach to Data Management6.20Designing DatabasesConceptual(logical)design:abstract model from business perspectivePhysical design:How database is arranged on direct-access storage devicesDesign process identifiesRelationships among data elements,redundant database elementsMost efficient way to group data elements to meet business requirements,needs of application programsNormalizationStreamlining complex groupings of data to minimize redundant data elements and awkward many-to-many relationshipsManagement Information SystemsManagement Information SystemsChapter 6 Foundations of Business Intelligence:Databases Chapter 6 Foundations of Business Intelligence:Databases and Information Managementand Information ManagementThe Database Approach to Data Management6.21Management Information SystemsManagement Information SystemsChapter 6 Foundations of Business Intelligence:Databases Chapter 6 Foundations of Business Intelligence:Databases and Information Managementand Information ManagementFigure 6-9An unnormalized relation contains repeating groups.For example,there can be many parts and suppliers for each order.There is only a one-to-one correspondence between Order_Number and Order_Date.An Unnormalized Relation for OrderAn Unnormalized Relation for OrderThe Database Approach to Data Management6.22Management Information SystemsManagement Information SystemsChapter 6 Foundations of Business Intelligence:Databases Chapter 6 Foundations of Business Intelligence:Databases and Information Managementand Information ManagementFigure 6-10After normalization,the original relation ORDER has been broken down into four smaller relations.The relation ORDER is left with only two attributes and the relation LINE_ITEM has a combined,or concatenated,key consisting of Order_Number and Part_Number.Normalized Tables Created from OrderNormalized Tables Created from OrderThe Database Approach to Data Management6.23Entity-relationship diagramUsed by database designers to document the data modelIllustrates relationships between entitiesDistributing databases:Storing database in more than one placePartitioned:Separate locations store different parts of databaseReplicated:Central database duplicated in entirety at different locations Management Information SystemsManagement Information SystemsChapter 6 Foundations of Business Intelligence:Databases Chapter 6 Foundations of Business Intelligence:Databases and Information Managementand Information ManagementThe Database Approach to Data Management6.24Management Information SystemsManagement Information SystemsChapter 6 Foundations of Business Intelligence:Databases Chapter 6 Foundations of Business Intelligence:Databases and Information Managementand Information ManagementFigure 6-11This diagram shows the relationships between the entities ORDER,LINE_ITEM,PART,and SUPPLIER that might be used to model the database in Figure 6-10.An Entity-Relationship DiagramAn Entity-Relationship DiagramThe Database Approach to Data Management6.25Distributing databasesTwo main methods of distributing a databasePartitioned:Separate locations store different parts of databaseReplicated:Central database duplicated in entirety at different locationsAdvantagesReduced vulnerabilityIncreased responsivenessDrawbacksDepartures from using standard definitionsSecurity problemsManagement Information