@Override
  public boolean shouldConvertDecimal64ToDecimal() {
    return false;
  }
Compute IF(expr1, expr2, expr3) for 3 input column expressions.
The first is always a boolean (LongColumnVector).
The second is a column or non-constant expression result.
The third is a constant value.
ql/src/java/org/apache/hadoop/hive/ql/exec/vector/expressions/IfExprDecimal64ScalarDecimal64Column.java