CS338 Lecture Notes - Lecture 10: Conceptual Schema, Social Security Number, Functional Requirement

• School: University of Waterloo
• Department: Computer Science
• Course: CS338
• Professor: Angela Bonifati

Document Summary

Er diagrams diagrammatic notation associated with er model. Requirements collection and analysis: db designers interview prospective db users to understand and document data requirements, data requirements, functional requirements of principal application. Conceptual or logical db design: description of data requirements, detailed descriptions of components and constraints, transformed into implementation data model, get db schema in implementation data model of dbms. Internal storage structures, file organizations, indexes, access paths, physical design parameters for db files. Requirements gathered for company: employees, departments and projects, company organized into departments, departments controls several projects, employee: require each employees name, social security number, address, salary, sec. birth date, keep track of dependents of each employee. Described data in terms of: entities or entity sets: objects, relationships and relationship sets: connections between objects, attributes: properties that characterize or describe entities or relationships. Collection or set of similar entities that have same attributes. Employee & company = entity type tuples in employee = entity set.