Fundamentals of Database Systems Chapter 1

Fundamentals of Database Systems Chapter 1 Data ️ Known facts that can be recorded and that have implicit meaning. Database ️ A collection of related data. Universe of Discourse (UoD) ️ An aspect of the real world a database represents, also known as miniworld. Database Management System (DBMS) ️ A computerized system that enables users to create and maintain a database. Meta-Data ️ The database definition or descriptive information stored by the DBMS in the form of a database catalog or dictionary. Constructing ️ The process of storing the data on a storage medium that is controlled by the DBMS. Manipulation ️ Functions such as querying the database to retrieve specific data, updating the database to reflect changes in the miniworld, and gathering reports from the data. Sharing ️ Allows multiple users and programs to access the database simultaneously. Application Program ️ Accesses the database by sending queries and requests for data to the DBMS. Protection ️ Includes system protection against hardware or software malfunction and security protection against unauthorized or malicious access. Maintenance ️ A system's evolution as requirements change over time. Database System ️ The database and DBMS software together. Transaction ️ Causes some data to be read and some data to be written into the database. Queries ️ The accessing of different parts of data and formulating the result of a request. Catalog ️ Stores the description of a particular database. Program-Data Independence ️ Allows changing data structures and storage organization without having to change the DBMS access programs. Data Abstraction ️ Used to hide storage details and present the users with a conceptual view of the database. Concurrency Control ️ Guarantees that each transaction is correctly executed or aborted. Recovery Subsystem ️ Ensures each completed transaction has its effect permanently recorded in the database. Online Transaction Processing (OLTP) ️ A major part of database applications allowing hundreds of concurrent transactions to execute per second. Database Administrators ️ Responsible for authorizing access to the database, coordinating and monitoring its use, acquiring software and hardware resources, controlling its use, and monitoring efficiency of operations. Database Designers ️ Responsible to define the content, the structure, the constraints, functions or transactions against the database, and communicating with end-users and understanding their needs. End-Users ️ Use the data for queries, reports, and updating of database content. Casual End-User ️ Accesses database occasionally when needed.