ISYS2056 Lecture Notes - Lecture 8: Relational Database Management System, Telephone Directory, Database Model
Document Summary
A system that takes data as input and generates information as output. Processing in databases is usually hidden from business users. They don"t worry about how it"s done. They worry what goes in and what comes out. List on the wall of a coffee shop. A repository for an organised collection of interrelated data files, records and fields. A collection of related data organised to assist end-users. Keeping track of the files on your pc. Database management system (dbms) enables a pool of related data shared by multiple application programs. A collection of tables related to one another by common data elements. Idea: each data item is stored once in the entire system. Something that the business wishes to store data about. Can be a person place object, event. Associations or relationships between entities depend of the business rules. Provide a simple diagrammatic way of representing entities and the relationships between them. Eg: a bank branch has only one manager.
