@HiveDecimalVersionV1
  public BigDecimal bigDecimalValue() {
    return fastBigDecimalValue();
  }
Return a BigDecimal representing the decimal.  The BigDecimal class is able to accurately
represent the decimal.

NOTE: We are not representing our decimal as BigDecimal now as OldHiveDecimal did, so this
is now slower.
storage-api/src/java/org/apache/hadoop/hive/common/type/HiveDecimal.java