Execution example::

  select Users \
    --output_columns name,memo,_score \
    --filter 'query_parallel_or("name * 10 || memo", "alice", "Groonga")'
  # [
  #   [
  #     0, 
  #     1337566253.89858, 
  #     0.000355720520019531
  #   ], 
  #   [
  #     [
  #       [
  #         2
  #       ], 
  #       [
  #         [
  #           "name", 
  #           "ShortText"
  #         ], 
  #         [
  #           "memo", 
  #           "ShortText"
  #         ], 
  #         [
  #           "_score", 
  #           "Int32"
  #         ]
  #       ], 
  #       [
  #         "Alice", 
  #         "Groonga user", 
  #         11
  #       ], 
  #       [
  #         "Tobby", 
  #         "Groonga and Mroonga user. Mroonga is ...", 
  #         1
  #       ]
  #     ]
  #   ]
  # ]
