Spatial functions
Spatial functions can be used with geospatial data. For example, they allow you to calculate the distances between two points, the area of a polygon, and so on.
There can also be situations that require a merge of multiple geospatial data sets that are based on a spatial predicate (within, close to, and so on), which can be done through a merge condition.
Notes:
 These spatial functions don't apply to threedimensional data. If you import threedimensional data into a flow, only the first two dimensions are used by these functions. The zaxis values are ignored.
 Geospatial functions aren't supported.
Function  Result  Description 

close_to(SHAPE,SHAPE,NUM)

Boolean  Tests whether 2 shapes are within a certain DISTANCE of each other. If a projected coordinate system is used, DISTANCE is in meters. If no coordinate system is used, it is an arbitrary unit. 
crosses(SHAPE,SHAPE)

Boolean  Tests whether 2 shapes cross each other. This function is suitable for 2 linestring shapes, or 1 linestring and 1 polygon. 
overlap(SHAPE,SHAPE)

Boolean  Tests whether there is an intersection between 2 polygons and that the intersection is interior to both shapes. 
within(SHAPE,SHAPE)

Boolean  Tests whether the entirety of SHAPE1 is contained within a POLYGON. 
area(SHAPE)

Real  Returns the area of the specified POLYGON. If a projected system is used, the function returns meters squared. If no coordinate system is used, it is an arbitrary unit. The shape must be a POLYGON or a MULTIPOLYGON. 
num_points(SHAPE,LIST)

Integer  Returns the number of points from a point field (MULTIPOINT) which are contained within the bounds of a POLYGON. SHAPE1 must be a POLYGON or a MULTIPOLYGON. 
distance(SHAPE,SHAPE)

Real  Returns the distance between SHAPE1 and SHAPE2. If a projected coordinate system is used, the function returns meters. If no coordinate system is used, it is an arbitrary unit. SHAPE1 and SHAPE2 can be any geo measurement type. 