Execution example::

  load --table Memos
  [
  {
    "_key": "memo1",
    "title": "Groonga is easy",
    "content": "Groonga is very easy full text search engine!"
  },
  {
    "_key": "memo2",
    "title": "Mroonga is easy",
    "content": "Mroonga is more easier full text search engine!"
  },
  {
    "_key": "memo3",
    "title": "Rroonga is easy",
    "content": "Ruby is very helpful."
  },
  {
    "_key": "memo4",
    "title": "Groonga is fast",
    "content": "Groonga! Groonga! Groonga! Groonga is very fast!"
  },
  {
    "_key": "memo5",
    "title": "PGroonga is fast",
    "content": "PGroonga is very fast!"
  },
  {
    "_key": "memo6",
    "title": "PGroonga is useful",
    "content": "SQL is easy because many client libraries exist."
  },
  {
    "_key": "memo7",
    "title": "Mroonga is also useful",
    "content": "MySQL has replication feature. Mroonga can use it."
  }
  ]
  # [[0, 1337566253.89858, 0.000355720520019531], 7]
