code: func (r Row) GetDatumRow(fields []*types.FieldType) []types.Datum {
  	datumRow := make([]types.Datum, 0, r.c.NumCols())
  	for colIdx := 0; colIdx < r.c.NumCols(); colIdx++ {
  		datum := r.GetDatum(colIdx, fields[colIdx])
  		datumRow = append(datumRow, datum)
  	}
  	return datumRow
  }
docs: // GetDatumRow converts chunk.Row to types.DatumRow.
  // Keep in mind that GetDatumRow has a reference to r.c, which is a chunk,
  // this function works only if the underlying chunk is valid or unchanged.