Bài giảng Business Driven Technology - Chapter 7 Storing Organizational Information—Databases

CHAPTER 7Storing OrganizationalInformation—DatabasesLEARNING OUTCOMES7.1 Define the fundamental concepts of the relational database model7.2 Evaluate the advantages of the relational database model7.3 Compare relational integrity constraints and business-critical integrity constraintsLEARNING OUTCOMES7.4 Describe the benefits of a data driven website7.5 Describe the two primary methods for integrating information across multiple databasesRELATIONAL DATABASE FUNDAMENTALSInformation is everywhere in an organizationInformation is stored in databasesDatabase – maintains information about various types of objects (inventory), events (transactions), people (employees), and places (warehouses)RELATIONAL DATABASE FUNDAMENTALSDatabase models include:Hierarchical database model – information is organized into a tree-like structure (using parent/child relationships) in such a way that it cannot have too many relationshipsNetwork database model – a flexible way of representing objects and their relationshipsRelational database model – stores information in the form of logically related two-dimensional tablesEntities and AttributesEntity – a person, place, thing, transaction, or event about which information is storedThe rows in each table contain the entitiesIn Figure 7.1 CUSTOMER includes Dave’s Sub Shop and Pizza Palace entitiesAttributes (fields, columns) – characteristics or properties of an entity classThe columns in each table contain the attributesIn Figure 7.1 attributes for CUSTOMER include Customer ID, Customer Name, Contact NameKeys and RelationshipsPrimary keys and foreign keys identify the various entity classes (tables) in the databasePrimary key – a field (or group of fields) that uniquely identifies a given entity in a tableForeign key – a primary key of one table that appears an attribute in another table and acts to provide a logical relationship among the two tablesKeys and RelationshipsPotential relational database for Coca-ColaRELATIONAL DATABASE ADVANTAGESDatabase advantages from a business perspective includeIncreased flexibilityIncreased scalability and performanceReduced information redundancyIncreased information integrity (quality)Increased information securityIncreased FlexibilityA well-designed database should:Handle changes quickly and easilyProvide users with different viewsHave only one physical viewPhysical view – deals with the physical storage of information on a storage deviceHave multiple logical viewsLogical view – focuses on how users logically access information Increased Scalability and PerformanceA database must scale to meet increased demand, while maintaining acceptable performance levelsScalability – refers to how well a system can adapt to increased demandsPerformance – measures how quickly a system performs a certain process or transactionReduced Information RedundancyDatabases reduce information redundancyRedundancy – the duplication of information or storing the same information in multiple places Inconsistency is one of the primary problems with redundant informationIncrease Information Integrity (Quality)Information integrity – measures the quality of informationIntegrity constraint – rules that help ensure the quality of informationRelational integrity constraintBusiness-critical integrity constraint Increased Information SecurityInformation is an organizational asset and must be protectedDatabases offer several security features including:Password – provides authentication of the userAccess level – determines who has access to the different types of information Access control – determines types of user access, such as read-only accessDATABASE MANAGEMENT SYSTEMSDatabase management systems (DBMS) – software through which users and application programs interact with a databaseData-Driven WebsitesData-driven websites – an interactive website kept constantly updated and relevant to the needs of its customers through the use of a databaseData-Driven Website Business AdvantagesData-Driven Business IntelligenceBI in a data-driven websiteIntegrating Information among Multiple DatabasesIntegration – allows separate systems to communicate directly with each otherForward integration – takes information entered into a given system and sends it automatically to all downstream systems and processesBackward integration – takes information entered into a given system and sends it automatically to all upstream systems and processesIntegrating Information among Multiple DatabasesForward integration and backward integrationIntegrating Information among Multiple DatabasesBuilding a central repository specifically for integrated informationOPENING CASE STUDY QUESTIONSIt Takes A Village to Write an EncyclopediaIdentify the different types of entity classes that might be stored in Wikipedia’s database Explain why database technology is so important to Wikipedia’s business modelExplain the difference between logical and physical views and why logical views are important to Wikipedia’s customersCHAPTER SEVEN CASEKeeper of the KeysAlmost 90 million people had their personal information stolen or lost by organizationsBank of America: 1.2 million customersCardSystems: 40 million customersCitigroup: 3.9 million customersDSW Shoe Warehouse: 1.4 million customers.TJX Companies: 45.6 million customersWachovia: 676,000 customersCHAPTER SEVEN CASE QUESTIONSHow many organizations have your personal information, including your Social Security number, bank account numbers, and credit card numbers?What information is stored at your college? Is there any chance your information could be hacked and stolen from your college?What can you do to protect yourself from identity theft?CHAPTER SEVEN CASE QUESTIONSDo you agree or disagree with changing laws to hold the company where the data theft occurred accountable? Why or why not?What impact would holding the company liable where the data theft occurred have on large organizations?What impact would holding the company liable where the data theft occurred have on small business?