Computers: Tools for an Information Age Chapter 13 Database Management Systems: Getting Data Together Copyright © 2003 by Prentice Hall

Copyright © 2003 by Prentice Hall Objectives Describe the hierarchy of data Explain the differences between files and databases List the four database models Describe the concept of data integrity Describe the functions of a database management system Copyright © 2003 by Prentice Hall

Copyright © 2003 by Prentice Hall Objectives Describe the process of creating a database in general terms Compare and contrast relational and object-oriented databases Explain what a data warehouse is and how it differs from a database Copyright © 2003 by Prentice Hall

Copyright © 2003 by Prentice Hall The Hierarchy of Data Field – a group of one or more characters that has a specific meaning The smallest meaningful unit of data Describes one characteristic of a person, place, or thing Record – the set of fields containing data about a person, place, or thing File – a collection of related records Copyright © 2003 by Prentice Hall

Copyright © 2003 by Prentice Hall Files and Databases Traditionally, information systems were developed with a file processing approach Database approach creates separate files for each entity Copyright © 2003 by Prentice Hall

Copyright © 2003 by Prentice Hall Database Models Define the way a database organizes data Four main models Hierarchical Network Relational Object-oriented Copyright © 2003 by Prentice Hall

Copyright © 2003 by Prentice Hall Data Integrity Refers to the degree to which data is accurate and reliable Integrity constraints – rules all data must follow If integrity constraints are not followed, the data is unreliable Copyright © 2003 by Prentice Hall

Copyright © 2003 by Prentice Hall Database Management Database Management System (DBMS) – allows you to create a database and enter, modify, and retrieve data as needed Available at all levels Sophisticated systems for a mainframe environment Inexpensive, easy-to-use personal computer systems Copyright © 2003 by Prentice Hall

Copyright © 2003 by Prentice Hall Database Features Data dictionary Data maintenance Data retrieval Concurrency control Security Backup and recovery Copyright © 2003 by Prentice Hall

Creating and Using a Database Creating the database Determining the table structure Setting up the file structure Entering the data Using the database Copyright © 2003 by Prentice Hall

The Object-Oriented Database Model Designed to manipulate complex data types Examples include maps and audio and video files The object is the main focus Designed to incorporate object-oriented programming with large amounts of complex data Copyright © 2003 by Prentice Hall

Copyright © 2003 by Prentice Hall Data Warehouses Contain data that has been captured in company databases Can contain data that has been gathered from external sources Use a variety of analytical tools Copyright © 2003 by Prentice Hall