SPLIT subpartition_extended_name
  { AT ( literal [, literal]... )
    [ INTO (range_subpartition_desc, range_subpartition_desc) ]
  | VALUES ({ literal | NULL  [, literal | NULL ]...})
    [ INTO (list_subpartition_desc, list_subpartition_desc) ]
  | INTO ( { range_subpartition_desc [, range_subpartition_desc ]...
           | list_subpartition_desc [, list_subpartition_desc ]... }
         , subpartition_spec )
  } [ dependent_tables_clause ]
    [ update_index_clauses ]
    [ parallel_clause ]