ITM 102 Lecture Notes - Data Manipulation Language, Data Definition Language, Sql

• School: Ryerson University
• Department: Information Technology Management
• Course: ITM 102
• Professor: Franklyn Prescod

Document Summary

Information cannot flow freely across different functional areas or different parts of the organization. A database management system(dbms) is software that permits an organization to centralize data, manage them efficiently, and provide access to the stored data by application programs. How a dbms solves the problems of the traditional file environment: a dbms reduces data redundancy and inconsistency by minimizing isolated files in which the same data are repeated. Relational dbms: represents data as two-dimensional tables called relations, relates data across tables based on common data element, examples: access, db2, oracle, ms sql server. Operations of a relational dbms: select: creates subset of rows that meet specific criteria. Join: combines relational tables to provide users with information: project: enables users to create new tables containing only relevant information. Object-oriented dbms: stores data and procedures as objects that can be retrieved and shared automatically, provides capabilities of both object-oriented and relational dbms. Hybrid oodbms: combine benefits of relational and object-oriented dbms.