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1、McGraw-Hill/IrwinCopyright 2008 by The McGraw-Hill Companies,Inc.All rights reserved.Chapter 12Databases12-2Competencies(Page 1 of 2)Distinguish between the physical and logical view of dataDescribe how data is organized:characters,fields,records,files,and databasesDescribe databases,database issues
2、,and database management systems(DBMS)Page 34412-3Competencies(Page 2 of 2)Describe five data models:hierarchical,network,relational,multidimensional,and object-orientedDistinguish among individual,company,distributed,proprietary,and Web databasesRecognize strategic database uses and security concer
3、nsPage 34412-4Introduction to DatabasesMuch like a library,secondary storage is designed to store information.End users need to understand how such stored information is organized using data field,records,files and databases.There are different types of databases and structures.To be a competent use
4、r of information in the information age end users need to be able to find information that is stored in databases.Page 34512-5Data Examples of data include:Facts or observations about people,places,things,and events Audio captured,music captured,photographs and videoTwo ways to view dataPhysical vie
5、wLogical view Page 34612-6Data Organization CharacterFieldRecordFileTableDatabaseKey FieldBatch Versus Real-Time ProcessingPage 34612-7Key FieldUnique identifier also known as primary fieldCommon examplesSocial security numberStudent Identification NumbersEmployee Identification NumbersPart NumbersI
6、nventory NumbersPage 347Return12-8Batch Versus Real-time Processing(Page 1 of 2)Batch processing-data is collected over a period of time and the processing happens later all at one timePage 34812-9Batch Versus Real-Time Processing(Page 2 of 2)Real-time processing-happens immediately when the transac
7、tion occursPage 34812-10DatabasesCollection of integrated data logically related files and recordsDatabases address data redundancy and data integrityNeed for databasesDatabase ManagementPage 34912-11Need for DatabasesSharingSecurityLess data redundancyData integrityPage 350Access data entry formRet
8、urn12-12Database ManagementDBMS engineData definition subsystemData manipulation subsystemQuery-by-exampleStructured query language(SQL)Application generation subsystemData administration subsystemPage 35012-13DBMS StructureDBMS programs are designed to work with data that is logically structured or
9、 arrangedData models define rules and standards for data in a database the five widely used data models are:Hierarchical databaseNetwork databaseRelational databaseMultidimensional databaseObject-oriented databasePage 35212-19Types of Databases Individual Company or sharedDistributedProprietaryWebPa
10、ge 35612-20Individual DatabasesAlso called a microcomputer databaseIntegrated file collection for one person usually under the persons direct controlGenerally stored on the users hard-disk drive or on a LAN file serverReturnPage 36812-21Company or Shared DatabasesMay be stored on a mainframe and man
11、aged by a database administratorProvides access to users throughout a company2 Types of company or shared databasesCommon operational databaseCommon user databaseReturnPage 35612-22Distributed DatabasesDatabase is located in a place or places other than where users are locatedTypically database serv
12、ers on a client/server network provide the link between users and the distant dataReturnPage 35712-23Proprietary DatabasesGenerally an enormous database developed by an organization to cover particular subjectsAccess is offered to the public or selected outside individuals for a feeMost proprietary
13、databases are designed for organizational and individual useAlso referred to as information utilities or data banksReturnPage 35712-24Web DatabasesDistinguishing feature is that the database is available over the webWeb search engines interact with databasesWeb databases incorporate special interfac
14、e programs that create input forms,accept input,and send the data to the Web databasePage 35712-25Database Uses and IssuesStrategic usesSpecial type of database called data warehouseData mining used to search database SecurityDatabases are valuableProtection necessary Page 358Electronic fingerprint
15、pads12-26Careers In ITDatabase administrators determine the most efficient ways to organize and access a companys dataTypically responsible for maintaining database security and backing up the systemEmployers look for individuals with a bachelors degree in computer science and technical experienceDa
16、tabase administrators can expect to earn$44K-$81K annuallyPage 35912-27A Look to the FutureXperantoEnhancement to searching for dataAccess to structured(relational databases)and unstructured data(word processing and spreadsheet files)Page 36012-28Discussion Questions(Page 1 of 2)Describe the five lo
17、gical data groups or categories.What is the difference between batch processing and real-time processing?Identify and define the five part of DBMS programs.Page 36912-29Discussion Questions(Page 2 of 2)What are the five types of databases?Why does more than one kind of database exist?What are some of the benefits and limitations of databases?Why is security a concern?Page 369