Classify different types of spatial queries based on their spatial relationships, using a systematic taxonomy.
Spatial information retrieval is fundamental in modern applications that enhance data analysis by enabling the representation, storage, and management of spatial data. Spatial database systems and Geographical Information Systems are essential tools for those applications, offering efficient spatial data representation and spatial query processing. Spatial data is usually represented by geometries in Euclidean space, such as points, lines, and regions. Spatial query processing mainly relies on the task of retrieving spatial objects meeting specific spatial conditions. These conditions are often defined by spatial relationships, which describe how spatial objects relate within a given space and have different semantics, such as topological relationships (e.g., overlap, inside), metric relationships (e.g., distance), and direction relationships (e.g., cardinal directions). A typical spatial query finds all objects in a specified relationship with a search object. This article systematically explores the design and definition of spatial queries by using spatial relationships as their main foundation. By introducing both intuitive and formal definitions of various types of spatial queries, it helps users to understand each query’s practical use and underlying mechanics.