ICT 202 Lecture Notes - Lecture 56: Data Redundancy, Relational Database, Data Integrity

• School: University of Kentucky
• Department: Information Communication Technology
• Course: ICT 202
• Professor: Nicholas Proferes

Document Summary

Each department has its own set of files. Can be more complex than a file processing system. A data model defines how users view the organization of the data. A relational database organizes data into one or more tables (or relations ) of columns and rows, with a unique key identifying each row. Rows are also called records or tuples. Generally, each table/relation represents one entity type (such as customer or product) The rows represent instances of that type of entity and the columns representing values attributed to that instance (such as address or price) A data dictionary contains data about each file in the database and each field in those files. A dbms provides several tools that allow users and programs to retrieve and maintain data in the database. A query is a request for specific data from the database.