21.6. Spatial Databases
Spatial databases keep track of objects in a multidimensional space. Spatial data support in databases is important for efficiently storing, indexing and querying of data based on spatial locations. For example, we can use standard index structures (such as B-trees or hash indices) for storing a set of polygons in a database and to query the database to find all polygons that intersect a given polygon. Efficient processing of this query would require special-purpose index structures, such as R-trees for the task, which has been discussed in section 21.6.5.
21.6.1. Spatial Data
A common example of spatial data includes geographic data, such as road maps and associated information. A road map is a two-dimensional object ...