docs: @Override
      Type getDataType() {
          switch (opType) {
          case OpTypes.WINDOWED_RANK:
          case OpTypes.WINDOWED_DENSE_RANK:
          case OpTypes.WINDOWED_ROW_NUMBER:
          case OpTypes.WINDOWED_COUNT:
              return Type.SQL_BIGINT;
          case OpTypes.WINDOWED_MAX:
          case OpTypes.WINDOWED_MIN:
          case OpTypes.WINDOWED_SUM:
          	return dataType;
          default:
              throw Error.error("Unsupported windowed function " + OpTypes.aggregateName(opType), "", 0);
          }
      }