A relational model and SQL-like query language for spatial databases

Abstract

Spatial databases have experienced enormous growth in application environments, such as agriculture, environmental studies, geography, geology, city-planning, aerospace industry etc. More recently spatial databases have attracted attention in the database community. A considerable research has been done in physical implementation of spatial databases. This is particularly true of access methods for spatial data [238, 483, 512, 230, 231, 39, 506]. On the other hand, abstract modeling and querying of spatial data have received relatively less attention. The need for such a study becomes even more important because of diverse techniques proposed for representing spatial regions. Like [440] we favor that the logical view and the physical implementation of spatial data should be considered orthogonal issues. The users should be given a simple view of data and freed of the worry of how it is physically represented. This is even more important because physical implementation will continue to be a topic of study for quite some time to come. Conventional database techniques are inadequate in spatial databases because of the spatial structure implicit in spatial querying. We present a model and an SQL-like query language called SpaSQL (read space-Q-L) for spatial data. Without tying ourselves down to a choice of representation of spatial regions, we propose certain desirable closure properties for them to make SpaSQL seamless.