@Test
  public void testCompareWithVarchar() {
    ExprNodeDesc nodeDesc = new ExprNodeColumnDesc(TypeInfoFactory.varcharTypeInfo, "_c0", null, false);
    testValidateUDFOnComparingBigInt(nodeDesc);
  }
Test that a bigint comparing with a string, varchar or char is not allowed by default.
ql/src/test/org/apache/hadoop/hive/ql/parse/type/TestBigIntCompareValidation.java