Geographic Information Systems: An Introduction, 3rd Edition

18.4 Technical Database Design

A thorough database design is essential, both for realizing the functions required and for determining:

• Scope, so that only relevant data are entered
• Ease of access to data
• Efficiency with which functions are executed
• Facility with which data are updated
• Receptiveness to new types of data
• Ease of restructuring data in the database

As discussed in Chapter 12, a data model provides the basis for a database design. The detailed design of a database depends on the system software and hardware chosen. In joint-use facilities, databases must be further designed for individual organization data or for data common to all the organizations involved.

The best approach is for each organization to design databases that best suit its specific needs, and to incorporate direct or indirect interorganizational communication via a joint solution (Figure 18.3). The various individual databases are accessed by a data communications network. The physical separation between the databases and the communication between them are not obvious to users, who access the entire network. The distributed database approach also requires good updating routines and extensive standardization.

Figure 18.3

In a joint system, some information may be available to all users, while parts of the total information set are stored in user databases. The different user systems (databases) are ...