@HiveDecimalVersionV1
  public HiveDecimal abs() {
    if (fastSignum() != -1) {
      return this;
    }
    HiveDecimal result = new HiveDecimal(this);
    result.fastAbs();
    return result;
  }
Take the absolute value of a decimal.
<p>
@return When the decimal is negative, returns a new HiveDecimal with the positive value.
        Otherwise, returns the current 0 or positive value object;
storage-api/src/java/org/apache/hadoop/hive/common/type/HiveDecimal.java