CMPT 354 Chapter Notes -Physical Data Model, Database, Nosql

• School: Simon Fraser University
• Department: Computing Science
• Course: CMPT 354
• Professor: Oliver Schulte

Document Summary

Database = a very large, integrated, permanent collection of data real world modeling. Entities (the students, courses, columns) Database management system (dbms) : software package designed to store and manage databases. Must move datasets between main memeory to secondary storage (buffers, addressing) Must protect data from inconsistiancy due to concurrent users. Data independence : (abstract view of data) and efficient access) Concurrent access, recovery from crashes. Data models = collection of concepts from describing data. Schema : description of particular collection of data using data model and data definition language. Data def language : creating objects, such as tables. Data manip language : changing data, such as queries. Relation model of data: most widely used. Relation: tables with rows and columns. Students (side: stringe, name :string, login: string ) Relations stored as unordered files. How these schemas are physically stored in memory externima schema (view):course_info (cid, string, enrolment ) Schema : description of the columns or fields.