Chapter 1In this chapter, you will learn:Introducing the DatabaseDatabase ManagementImportance of DBMSDBMS Manages InteractionDatabase DesignHistorical Roots of DatabaseFile TerminologySimple File SystemFile System CritiqueFile System Critique (con’t.)Slide 13Slide 14Database SystemsDatabase vs. File SystemsDatabase System EnvironmentDatabase System TypesDBMS FunctionsDatabase ModelsDatabase Models (con’t.)Hierarchical Database ModelSlide 23Network Database ModelSlide 25Relational Database ModelRelational Database Model (con’t.)Slide 28Slide 29Entity Relationship Database ModelSlide 31Object-Oriented Database ModelOO Data ModelDatabase Models and the Internet1Chapter 1File Systems and DatabasesDatabase Systems: Design, Implementation, and Management, Fifth Edition, Rob and CoronelDatabase Systems: Design, Implementation, & Management, 5th Edition, Rob & Coronel21In this chapter, you will learn:•What a database is, what it does, and why database design is important•How modern databases evolved from files and file systems•About flaws in file system data management•What a DBMS is, what it does, and how it fits into the database system•About types of database systems and database modelsDatabase Systems: Design, Implementation, & Management, 5th Edition, Rob & Coronel31Introducing the Database•Data versus Information–Data constitute building blocks of information–Information produced by processing data–Information reveals meaning of data–Good, timely, relevant information key to decision making–Good decision making key to organizational survivalDatabase Systems: Design, Implementation, & Management, 5th Edition, Rob & Coronel41Database Management•Database is shared, integrated computer structure housing:–End user data–Metadata•Database Management System (DBMS)–Manages Database structure–Controls access to data–Contains query languageDatabase Systems: Design, Implementation, & Management, 5th Edition, Rob & Coronel51Importance of DBMS•Makes data management more efficient and effective•Query language allows quick answers to ad hoc queries•Provides better access to more and better-managed data•Promotes integrated view of organization’s operations •Reduces the probability of inconsistent dataDatabase Systems: Design, Implementation, & Management, 5th Edition, Rob & Coronel61DBMS Manages InteractionFigure 1.2Database Systems: Design, Implementation, & Management, 5th Edition, Rob & Coronel71Database Design•Importance of Good Design–Poor design results in unwanted data redundancy–Poor design generates errors leading to bad decisions•Practical Approach–Focus on principles and concepts of database design–Importance of logical designDatabase Systems: Design, Implementation, & Management, 5th Edition, Rob & Coronel81Historical Roots of Database•First applications focused on clerical tasks•Requests for information quickly followed•File systems developed to address needs–Data organized according to expected use–Data Processing (DP) specialists computerized manual file systemsDatabase Systems: Design, Implementation, & Management, 5th Edition, Rob & Coronel91File Terminology•Data –Raw Facts•Field–Group of characters with specific meaning•Record–Logically connected fields that describe a person, place, or thing•File–Collection of related recordsDatabase Systems: Design, Implementation, & Management, 5th Edition, Rob & Coronel101Simple File SystemFigure 1.5Database Systems: Design, Implementation, & Management, 5th Edition, Rob & Coronel111File System Critique•File System Data Management–Requires extensive programming in third-generation language (3GL)–Time consuming–Makes ad hoc queries impossible–Leads to islands of informationDatabase Systems: Design, Implementation, & Management, 5th Edition, Rob & Coronel121File System Critique (con’t.)•Data Dependence–Change in file’s data characteristics requires modification of data access programs–Must tell program what to do and how–Makes file systems cumbersome from programming and data management views•Structural Dependence–Change in file structure requires modification of related programsDatabase Systems: Design, Implementation, & Management, 5th Edition, Rob & Coronel131File System Critique (con’t.)•Field Definitions and Naming Conventions–Flexible record definition anticipates reporting requirements–Selection of proper field names important–Attention to length of field names–Use of unique record identifiersDatabase Systems: Design, Implementation, & Management, 5th Edition, Rob & Coronel141File System Critique (con’t.)•Data Redundancy–Different and conflicting versions of same data–Results of uncontrolled data redundancy•Data anomalies–Modification–Insertion–Deletion•Data inconsistency–Lack of data integrityDatabase Systems: Design, Implementation, & Management, 5th Edition, Rob & Coronel151Database Systems•Database consists of logically related data stored in a single repository•Provides advantages over file system management approach–Eliminates inconsistency, data anomalies, data dependency, and structural dependency problems–Stores data structures, relationships, and access pathsDatabase Systems: Design, Implementation, & Management, 5th Edition, Rob & Coronel161Database vs. File SystemsFigure 1.6Database Systems: Design, Implementation, & Management, 5th Edition, Rob & Coronel171Database System EnvironmentFigure 1.7Database Systems: Design, Implementation, & Management, 5th Edition, Rob & Coronel181Database System Types•Single-user vs. Multiuser Database–Desktop–Workgroup–Enterprise•Centralized vs. Distributed•Use–Production or transactional–Decision support or data warehouseDatabase Systems: Design, Implementation, & Management, 5th Edition, Rob & Coronel191DBMS Functions•Data dictionary management•Data storage management•Data transformation and presentation•Security management•Multiuser access control•Backup and recovery management•Data integrity management•Database language and application programming interfaces •Database communication interfacesDatabase Systems: Design, Implementation, & Management, 5th Edition, Rob & Coronel201Database Models•Collection of logical constructs used to represent data structure and relationships within the database–Conceptual models: logical nature of data representation–Implementation models: emphasis on