Execution example::

  select Entries --output_columns '_id, _key' --limit 1
  # [
  #   [
  #     0, 
  #     1337566253.89858, 
  #     0.000355720520019531
  #   ], 
  #   [
  #     [
  #       [
  #         5
  #       ], 
  #       [
  #         [
  #           "_id", 
  #           "UInt32"
  #         ], 
  #         [
  #           "_key", 
  #           "ShortText"
  #         ]
  #       ], 
  #       [
  #         1, 
  #         "The first post!"
  #       ]
  #     ]
  #   ]
  # ]