@Test
  public void testStdSampDecimal () throws HiveException {
      testAggregateDecimal(
        "Decimal",
        "stddev_samp",
        2,
        Arrays.asList(new Object[]{
                HiveDecimal.create(13),
                HiveDecimal.create(5),
                HiveDecimal.create(7),
                HiveDecimal.create(19)}),
        Math.sqrt(40));
  }
Unit test for the vectorized GROUP BY operator.
ql/src/test/org/apache/hadoop/hive/ql/exec/vector/TestVectorGroupByOperator.java