text: --Chapter 7
  --Recipe 9
  
  --How to do it
  --Step 1.
  DROP TABLE IF EXISTS chp07.uas_tin;
  CREATE TABLE chp07.uas_tin AS WITH pts AS 
  (
     SELECT
        PC_Explode(pa) AS pt 
     FROM
        chp07.uas_flights
  )
  SELECT
     ST_DelaunayTriangles(ST_Union(pt::geometry), 0.0, 2) AS the_geom 
  FROM
     pts;
  
  
  
  