@Deprecated
  @HiveDecimalVersionV1
  public HiveDecimal setScale(int serializationScale) {
    HiveDecimal result = new HiveDecimal(this);
    result.fastSetSerializationScale(serializationScale);
    return result;
  }
DEPRECATED for V2.
<p>
Create a decimal from another decimal whose only change is it is MARKED and will display /
serialize with a specified scale that will add trailing zeroes (or round) if necessary.
<p>
After display / serialization, the MARKED object is typically thrown away.
<p>
A MARKED decimal ONLY affects these 2 methods since these were the only ways setScale was
used in the old code.
<p>
   toString
   unscaleValue
<p>
This method has been deprecated because has poor performance by creating a throw away object.
<p>
For setScale(scale).toString() use toFormatString(scale) instead.
For setScale(scale).unscaledValue().toByteArray() use V2 bigIntegerBytesScaled(scale) instead.
<p>
For better performance, use the V2 form of toFormatString that takes a scratch buffer,
or even better use toFormatBytes.
<p>
And, use the form of bigIntegerBytesScaled that takes scratch objects for better performance.
storage-api/src/java/org/apache/hadoop/hive/common/type/HiveDecimal.java