@Test
  public void test8() throws ParseException {
    ASTNode ast = parse("MERGE INTO target USING source ON target.pk = source.pk WHEN MATCHED AND a = 1 THEN UPDATE set a = b WHEN MATCHED THEN DELETE");
  }
both UPDATE and INSERT
@throws ParseException
parser/src/test/org/apache/hadoop/hive/ql/parse/TestMergeStatement.java