A Comparison of the Hierarchical, Network, and Relational, Database Models
with the other two models. Changes to the database structure must be reflected in the application as well. Compatible with the other two models. However, changes to database structure usually require changes in the application. Compatible with the other two models. The database structure is transparent.
Queries No query language unless it is predefined in to application. User needs to know the structure in order to query information. Versatile query language. Includes ability to run ad hoc queries.
Data integrity Plagued with redundancy due to the child/parent limitations Less redundancy than the hierarchical model. Since the network model is navigational it becomes harder to maintain integrity as the database’s complexity increases. Logical rules guarantee imposition of integrity constraints.
Changes Changes to the structure are difficult to implement since the entire structure is predefined. Changes to the structure are difficult to implement since the entire structure is predefined. Changes are easy to implement since the structure is transparent to the user and the application.
References
Hernandez, M. (1997). What is a relational database? Database design for mere mortals: A hands-on guide to relational database design, Chapter 1. Retrieved July 3, 2003 from Safari Tech Books Online on the World Wide Web: http://safari.bvdep.com/