{ allocate_extent_clause
| deallocate_unused_clause
| shrink_clause
| { LOB LOB_item |  VARRAY varray }
  modify_LOB_parameters
    [ { LOB LOB_item | VARRAY varray }
      modify_LOB_parameters
    ] ...
| [ REBUILD ] UNUSABLE LOCAL INDEXES
| { ADD | DROP } VALUES (value[, value ]...)
}