Given a spatiallyenabled DBMS explain the purpose of a GISre

Given a spatially-enabled DBMS, explain the purpose of a GIS-related bounding box/bounding rectangle/bounding polygon function. Assuming that the DBMS does not provide a circular spatial bounding function (point, radius), explain how a bounding polygon function could be developed to provide a substitute for this function, and how accuracy of this approximation might be increased.

Solution

Ans.

Purpose of GIS related bounding entities: They aim at defining the objects and their shapes. Owing to their simplicity of expression and ease of use for searching, bounding entities are also commonly included in relevant standards for geospatial metadata, i.e. metadata that describes spatial (geographic) objects.

To define a circular spatial bounding function:
We can use a bounding polygon function in the following manner:
circleFunction(x1, y1, r), where x1, y1 is the centre of the polygon and r is the distance between centre to the side of the polygon assuming polygon to have 0 vertex.