Database Systems: Lecture 1 - Database System Concepts and Architecture presents about File-based Approach, Database Approach, Three-Schema Architecture and Data Independence, Database Languages, Data Models, Database Schema and Database State, Data Management Systems Framework. | Database System Concepts and Architecture ) Outline File-based Approach Database Approach Database Systems Roles in the Database Environment DBMSs Three-Schema Architecture and Data Independence Database Languages Data Models, Database Schema and Database State Data Management Systems Framework Where are we? Extending database capabilities for new applications Reading Suggestion: [1,2]: Chapters 1, 2 File-based Approach Data is stored in one or more separate computer files Data is then processed by computer programs - applications File-based Approach File-based Approach Problems/Limitations Data Redundancy Data Inconsistency More details: see [2] File-based approach Shared file approach File-based Approach Shared File Approach Data (files) is shared between different applications Data redundancy problem is alleviated Data inconsistency problem across different versions of the same file is solved Other problems: Rigid data structure: If applications have to . | Database System Concepts and Architecture ) Outline File-based Approach Database Approach Database Systems Roles in the Database Environment DBMSs Three-Schema Architecture and Data Independence Database Languages Data Models, Database Schema and Database State Data Management Systems Framework Where are we? Extending database capabilities for new applications Reading Suggestion: [1,2]: Chapters 1, 2 File-based Approach Data is stored in one or more separate computer files Data is then processed by computer programs - applications File-based Approach File-based Approach Problems/Limitations Data Redundancy Data Inconsistency More details: see [2] File-based approach Shared file approach File-based Approach Shared File Approach Data (files) is shared between different applications Data redundancy problem is alleviated Data inconsistency problem across different versions of the same file is solved Other problems: Rigid data structure: If applications have to share files, the file structure that suits one application might not suit another Physical data dependency: If the structure of the data file needs to be changed in some way, this alteration will need to be reflected in all application programs that use that data file No support of concurrency control: While a data file is being processed by one application, the file will not be available for other applications or for ad hoc queries Outline File-based Approach Database Approach Database Systems Roles in the Database Environment DBMSs Three-Schema Architecture and Data Independence Database Languages Data Models, Database Schema and Database State Data Management Systems Framework Where are we? Extending database capabilities for new applications Reading Suggestion: [1,2]: Chapters 1, 2 Database Approach Arose because: Definition of data was embedded in application programs, rather than being stored separately and independently No control over access and manipulation of data beyond
