Execution example::

  select Memos --output_columns _key,tag --filter 'in_values(tag, "groonga", "mroonga", "droonga")' --sortby _id
  # [
  #   [
  #     0, 
  #     1337566253.89858, 
  #     0.000355720520019531
  #   ], 
  #   [
  #     [
  #       [
  #         4
  #       ], 
  #       [
  #         [
  #           "_key", 
  #           "ShortText"
  #         ], 
  #         [
  #           "tag", 
  #           "ShortText"
  #         ]
  #       ], 
  #       [
  #         "Groonga is fast", 
  #         "groonga"
  #       ], 
  #       [
  #         "Mroonga is fast", 
  #         "mroonga"
  #       ], 
  #       [
  #         "Droonga is fast", 
  #         "droonga"
  #       ], 
  #       [
  #         "Groonga is a HTTP server", 
  #         "groonga"
  #       ]
  #     ]
  #   ]
  # ]
