@HiveDecimalVersionV1
  public HiveDecimal subtract(HiveDecimal dec) {
    HiveDecimal result = new HiveDecimal();
    if (!fastSubtract(
        dec,
        result)) {
      return null;
    }
    return result;
  }
Subtract from the current decimal another decimal and return the result.
storage-api/src/java/org/apache/hadoop/hive/common/type/HiveDecimal.java