Management of Information Systems: 45-870AgendaAnnouncementsIn-Class ExerciseThe IT ArchitectureKey DefinitionsDisadvantages of Traditional File Processing SystemsAdvantages of a Database ApproachDatabase ConceptsSlide 10Slide 11Slide 12Slide 13Database StructuresSlide 15Hierarchical Data StructureSlide 17Network Data StructureSlide 19Relational Data StructureSlide 21Object Oriented structureNormalizing Database StructuresSteps in “normalizing” dataPowerPoint PresentationSales Report Data: Additional InformationSlide 27Slide 28Slide 29Normalized Relations for this DataFrom Normalized Relations to an Entity Relationship DiagramEntity Relationship Diagram ExampleIT Exercise IIFrom an ERD to a Database in Access2000Thursday, January 27, 2000 1Management of Information Systems: 45-870Mini-3Spring 2000Thursday, January 27, 2000 2AgendaAnnouncements and RemindersTechnology Byte PresentationsIn-Class Exercise Designing and Creating Databases Data/Database Definitions and ConceptsDatabase StructuresIT Exercise II AssignedUsing Access2000 to Create Relational DatabasesThursday, January 27, 2000 3AnnouncementsTechnology Byte PresentationsToday (1/27):Section A: E-Team, TigersSection B: E-Sales, The MastersTuesday (2/1):Section A: DeathSpiral.Com, E-SixpackSection B: Jeree’s Kids, Hot TaMaLesIT Exercise I Due TodayThursday, January 27, 2000 4In-Class ExerciseReflection on IT Exercise I:Pros and cons of using an HTML generator (specifically FrontPage)Reflections on useWhat process did you use as a team to do this assignment?What aspects of your process were effective? Problematic?How do you feel about your end product? Based on this experience, what managerial concerns or challenges do you have in relation to developing web pages for company intra/ inter/ extranets?Thursday, January 27, 2000 5HARDWARESOFTWARE & DATATELECOMMUNICATIONSThe IT ArchitectureThursday, January 27, 2000 6Key DefinitionsData:Information:File:Database:Metadata:Thursday, January 27, 2000 7Disadvantages of Traditional File Processing SystemsData DependenceData RedundancyLimited Data SharingLong Development TimesExcessive MaintenanceThursday, January 27, 2000 8Advantages of a Database ApproachMinimal Data RedundancyData IntegrationData IndependenceImproved Data SharingEnforcement of Consistent Standards and ConstraintsBetter AccessSecurity, Backup/Recovery, ConcurrencyThursday, January 27, 2000 9Database ConceptsEntities:Examples:Thursday, January 27, 2000 10Database ConceptsRelationships:Types:1:11:M or M:1M:MThursday, January 27, 2000 11Database ConceptsAttributes:Examples:Thursday, January 27, 2000 12Database ConceptsRecords:Example:Thursday, January 27, 2000 13Database ConceptsKeys:Types and Examples:Thursday, January 27, 2000 14Database StructuresPhysical Structure: how data is stored on and accessed from tape or disk.Logical Structure: how the data is perceived by the user.communication tooldesign aidThursday, January 27, 2000 15Database Structures3 common logical DB structuresHierarchicalNetworkRelational (most popular)newest logical DB structureObject OrientedThursday, January 27, 2000 16Hierarchical Data Structure7345 | Professor | Ludwigsohn | Comp.Sci.Winter 1995 | 2 |Promotions Fall 1996 | 3 |NoneIntro | 7001 | 3 | 45 VBasic | 7232 | 4 | 25VBasic2 | 7233 | 4 | 25Thursday, January 27, 2000 17Hierarchical Data StructureRequires well-defined, prespecified access path; supports 1:MGood for applications that involve very few types of queries but lots of dataVery efficient but inflexibleNot appropriate for business usersThursday, January 27, 2000 18Network Data Structure7345 | Professor | Ludwigsohn | Comp.Sci.Winter 1995 | 2 |Promotions Fall 1996 | 3 |NoneIntro | 7001 | 3 | 45 VBasic | 7232 | 4 | 25VBasic2 | 7233 | 4 | 25Thursday, January 27, 2000 19Network Data StructureMore flexible (supports M:M) but still requires pre-specified pathNot as efficient; must limit links among files or volume of dataDifficult to modify and add links between filesNot appropriate for business usersThursday, January 27, 2000 20Relational Data StructureDept Chair Address PhoneCompSci Miller BT 250 4-3555English Russo HHH 540 4-5333CourseNameCourse# Credits Prof-ID EnrollCapIntro 7001 3 7345 45VBasic 7232 4 7345 25VBasic2 7233 4 7345 25Faculty TableDept TableCourse TableFac-ID Name Rank Dept7345 Ludwigsohn Professor CompSci5290 Russo AssocProf EnglishThursday, January 27, 2000 21Relational Data StructureMost flexible; if two tables share a field, they can be linkedMay not be efficient for high transaction volumesEasy to modifyMost appropriate for business usersThursday, January 27, 2000 22Object Oriented structurenot yet widely used in practicepassive: separates object attributes from methodsactive: stores object attributes and methods togetherThursday, January 27, 2000 23Normalizing Database Structures Why does anyone need to do this:– redundancy – update efficiency– possible inconsistenciesThursday, January 27, 2000 24Steps in “normalizing” data1. break repeating groups of fields into separate entities, each with its own unique key (first normal form)2. Identify fields that are facts about only a portion of a key. Split into separate entities. (second normal form)3. Identify fields that are facts about some other non-key field. Split into separate entities. (third normal form)Thursday, January 27, 2000 25EXAMPLE: Sales Report DataEXAMPLE: Sales Report DataData includes: Sales Person # Sales Person Name Sales Area Customer Name Customer Number Warehouse Number Warehouse Location Sales AmountThursday, January 27, 2000 26Sales Report Data: Additional InformationOnly one number is assigned to each sales personOnly one number is assigned to each customerOnly one number is assigned to each warehouseA salesperson serves many customersA customer generates many salesCustomers receive their items from one warehouseThursday, January 27, 2000 27Step#1: Pull out repeating groups (First Normal Form)Step#1: Pull out repeating groups (First Normal Form)FROM:SalesReport (SalesPerson#, SalesPerson-Name, Sales-Area,Customer#, Customer-Name, Warehouse#,Warehouse-Location, Sales-Amount)TO:SalesPerson (SalesPerson#, SalesPerson-Name,