The objective is to identify all DeviceLocations that are close (within 50 meters) to some "point of interest". The points of interest are represented as circles with a center and a radius.

There are two different solutions here

• xsocialRDD.scala -- A basic RDD solution. To avoid comparing every DeviceLocation to every Point Of Interest, the world is divided into a grid and DeviceLocations are only compared to Points Of Interest in nearby grid cells.

• xsocialSql.scala -- A spark SQL solution that joins the DeviceLocations to Points of Interest using a where clause that should filter most (DeviceLocation, PointOfInterest) that are not close.

• xsocial.scala -- Code shared between the two solutions.

• app.scala -- A class with a main method that runs spark locally using the Spark SQL implementation

• testXSocial.scala -- A simple unit test.