ABSTRACT
Recent years have been characterized by a dramatic increase in the amount of digital data. It has been estimated by some analysts that the amount of information in the world doubles every 20 months, a process that results in an ever-increasing number of databases and clearinghouses. Spatial data and related data follow a similar pattern: as it is estimated that almost 80 percent of all databases have a spatial component, spatial databases are likely to follow a similar growth pattern. With recent advances in data collection, communication and storage on one hand, and with an increasing demand from users and service providers for richer and more up-to-date spatial data on the other hand, this trend may even intensify further in the near future.
