@Test
  public void testColUpper() throws HiveException {

    // no nulls, not repeating

    /* We don't test all the combinations because (at least currently)
     * the logic is inherited to be the same as testColLower, which checks all the cases).
     */
    VectorizedRowBatch batch = makeStringBatchMixedCase();
    StringUpper expr = new StringUpper(0, 1);
    batch.cols[0].noNulls = true;
    expr.evaluate(batch);
    BytesColumnVector outCol = (BytesColumnVector) batch.cols[1];
    int cmp = StringExpr.compare(mixedUpUpper, 0, mixedUpUpper.length, outCol.vector[0],
        outCol.start[0], outCol.length[0]);
    Assert.assertEquals(0, cmp);
    Assert.assertTrue(outCol.noNulls);
  }
Test vectorized expression and filter evaluation for strings.
ql/src/test/org/apache/hadoop/hive/ql/exec/vector/expressions/TestVectorStringExpressions.java