Execution example::

  table_list
  # [
  #   [
  #     0, 
  #     1337566253.89858, 
  #     0.000355720520019531
  #   ], 
  #   [
  #     [
  #       [
  #         "id", 
  #         "UInt32"
  #       ], 
  #       [
  #         "name", 
  #         "ShortText"
  #       ], 
  #       [
  #         "path", 
  #         "ShortText"
  #       ], 
  #       [
  #         "flags", 
  #         "ShortText"
  #       ], 
  #       [
  #         "domain", 
  #         "ShortText"
  #       ], 
  #       [
  #         "range", 
  #         "ShortText"
  #       ]
  #     ], 
  #     [
  #       256, 
  #       "Entries", 
  #       "/tmp/groonga-databases/commands_select.0000100", 
  #       "TABLE_HASH_KEY|PERSISTENT", 
  #       "ShortText", 
  #       "null"
  #     ], 
  #     [
  #       259, 
  #       "Terms", 
  #       "/tmp/groonga-databases/commands_select.0000103", 
  #       "TABLE_PAT_KEY|KEY_NORMALIZE|PERSISTENT", 
  #       "ShortText", 
  #       "null"
  #     ], 
  #     [
  #       262, 
  #       "Thesaurus", 
  #       "/tmp/groonga-databases/commands_select.0000106", 
  #       "TABLE_PAT_KEY|KEY_NORMALIZE|PERSISTENT", 
  #       "ShortText", 
  #       "null"
  #     ]
  #   ]
  # ]
