@Override
  public VectorExpressionDescriptor.Descriptor getDescriptor() {
    VectorExpressionDescriptor.Builder b = new VectorExpressionDescriptor.Builder();
    b.setMode(VectorExpressionDescriptor.Mode.PROJECTION)
        .setNumArguments(1)
        .setArgumentTypes(
            VectorExpressionDescriptor.ArgumentType.INT_FAMILY)
        .setInputExpressionTypes(
            VectorExpressionDescriptor.InputExpressionType.COLUMN);
    return b.build();
  }
To be used to cast long and boolean to decimal.
This works for boolean too because boolean is encoded as 0
for false and 1 for true.
ql/src/java/org/apache/hadoop/hive/ql/exec/vector/expressions/CastLongToDecimal64.java