MODIFY partition_extended_name
  { partition_attributes
  | { ADD | DROP } VALUES (literal[ , literal ]...)
  | { add_range_subpartition
    | add_list_subpartition
    | add_hash_subpartition 
    }
  | COALESCE SUBPARTITION [ update_index_clauses ][ parallel_clause ]
  | [ REBUILD ] UNUSABLE LOCAL INDEXES
  }