Introduction
Points
Linestrings
Polygons
Instruction
Great! One more exercise coming your way.
Exercise
Usually, a point signifies a place where a line bends. Help Mark find the routes with fewest bends so he can maintain a steady pace!
Find the average length among bicycle routes with fewer than 30 points. Provide the result in meters.
Stuck? Here's a hint!
To count the average, use the following construction:
AVG(ST_Length(ST_Transform(..., ...)))
Remember that the SRID for San Francisco with meters as the unit of measure is 26910.
To pick only routes with fewer than 30 points, write a proper WHERE condition using the ST_Npoints() function.
