run_query = fn(query_def) ->
  :timer.sleep(2000)
  "#{query_def} result"
end

#after 2 seconds -> "query 1 result"
run_query.("query 1")

# after 10 seconds result returns
1..5 |> Enum.map(&run_query.("query #{&1}"))

## spawning processes, returns a PID
spawn( fn -> IO.puts(run_query.("query_1")) end)

# async query
async_query = fn ( query_def) ->
  spawn( fn -> IO.puts(run_query.(query_def)) end)
end

# spawning 5 processes
1..5 |> Enum.map(&async_query.("query #{&1}"))
Enum.each(1..5, &async_query.("query #{&1}"))