Features of Spatial Databases
1) Spatial Measurements: Finds the distance between points, polygon area, etc.
2) Spatial Functions: Modify existing features to create new ones, for example by providing a buffer around them, intersecting features, etc.
3) Spatial- Predicates: Allows true/false queries such as 'is there a residence located within a mile of the area we are planning to build the landfill?
4) Constructor Functions: Creates new features with an SQL query specifying the vertices (points of nodes) which can make up lines. If the first and last vertex of a line is identical the feature can also be of the type polygon (a closed line).
5) Observer Functions: Queries that return specific information about a feature such as the location of the centre of a circle
