Solve and run DAG of tasks using Dask, or Ipyparallel, or custom executor
http://initd.org/psycopg/docs/usage.html http://initd.org/psycopg/docs/advanced.html#green-support http://www.dougalmatthews.com/notes/postgres-the-cool-stuff/
https://dask.pydata.org/en/latest/custom-graphs.html
https://ipyparallel.readthedocs.io/en/latest/dag_dependencies.html