@Test
  public void testDecimalColAddDecimalColumn() throws HiveException {
    VectorizedRowBatch b = getVectorizedRowBatch3DecimalCols();
    VectorExpression expr = new DecimalColAddDecimalColumn(0, 1, 2);
    DecimalColumnVector r = (DecimalColumnVector) b.cols[2];

    // test without nulls
    expr.evaluate(b);
    assertTrue(r.vector[0].getHiveDecimal().equals(HiveDecimal.create("2.20")));
    assertTrue(r.vector[1].getHiveDecimal().equals(HiveDecimal.create("-2.30")));
    assertTrue(r.vector[2].getHiveDecimal().equals(HiveDecimal.create("1.00")));

    // test nulls propagation
    b = getVectorizedRowBatch3DecimalCols();
    DecimalColumnVector c0 = (DecimalColumnVector) b.cols[0];
    c0.noNulls = false;
    c0.isNull[0] = true;
    r = (DecimalColumnVector) b.cols[2];
    expr.evaluate(b);
    assertTrue(!r.noNulls && r.isNull[0]);

    // Verify null output data entry is not 0, but rather the value specified by design,
    // which is the minimum non-0 value, 0.01 in this case.
    assertTrue(r.vector[0].getHiveDecimal().equals(HiveDecimal.create("0.01")));

    // test that overflow produces NULL
    b = getVectorizedRowBatch3DecimalCols();
    c0 = (DecimalColumnVector) b.cols[0];
    c0.vector[0].set(HiveDecimal.create("9999999999999999.99")); // set to max possible value
    r = (DecimalColumnVector) b.cols[2];
    expr.evaluate(b); // will cause overflow for result at position 0, must yield NULL
    assertTrue(!r.noNulls && r.isNull[0]);

    // verify proper null output data value
    assertTrue(r.vector[0].getHiveDecimal().equals(HiveDecimal.create("0.01")));

    // test left input repeating
    b = getVectorizedRowBatch3DecimalCols();
    c0 = (DecimalColumnVector) b.cols[0];
    c0.isRepeating = true;
    r = (DecimalColumnVector) b.cols[2];
    expr.evaluate(b);
    assertTrue(r.vector[0].getHiveDecimal().equals(HiveDecimal.create("2.20")));
    assertTrue(r.vector[1].getHiveDecimal().equals(HiveDecimal.create("2.20")));
    assertTrue(r.vector[2].getHiveDecimal().equals(HiveDecimal.create("2.20")));

    // test both inputs repeating
    DecimalColumnVector c1 = (DecimalColumnVector) b.cols[1];
    c1.isRepeating = true;
    expr.evaluate(b);
    assertTrue(r.isRepeating);
    assertTrue(r.vector[0].getHiveDecimal().equals(HiveDecimal.create("2.20")));

    // test right input repeating
    b = getVectorizedRowBatch3DecimalCols();
    c1 = (DecimalColumnVector) b.cols[1];
    c1.isRepeating = true;
    c1.vector[0].set(HiveDecimal.create("2.00"));
    r = (DecimalColumnVector) b.cols[2];
    expr.evaluate(b);
    assertTrue(r.vector[2].getHiveDecimal().equals(HiveDecimal.create("2.00")));
  }
Unit tests for vectorized arithmetic expressions.
ql/src/test/org/apache/hadoop/hive/ql/exec/vector/expressions/TestVectorArithmeticExpressions.java