Execution example::

  select Entries \
    --filter 'content *ONP "I Groonga"' \
    --output_columns content
  # [
  #   [
  #     0, 
  #     1337566253.89858, 
  #     0.000355720520019531
  #   ], 
  #   [
  #     [
  #       [
  #         1
  #       ], 
  #       [
  #         [
  #           "content", 
  #           "Text"
  #         ]
  #       ], 
  #       [
  #         "I started to use Groonga. It's very fast!"
  #       ]
  #     ]
  #   ]
  # ]
  select Entries \
    --filter 'content *ONP "Groonga I"' \
    --output_columns content
  # [[0, 1337566253.89858, 0.000355720520019531], [[[0], [["content", "Text"]]]]]
