In the previous chapters, we described geographical objects as points, lines, and polygons. In Chapters 8 and 9, you saw how to search geographical objects based on the way they are positioned with respect to other objects. In particular, you learned how to find objects that are within some distance from another object (with the
SDO_WITHIN_DISTANCE operator) or simply to find the object nearest to another one (with the
Those operations are useful, no doubt. However, they find and select objects based solely on the shortest absolute distance ("as the crow flies") between them. This may be very different from the actual distance you would need to travel to reach your destination. Unless you are a bird, ...