static void assertExplainHasString(String string, List<String> queryPlan, String errMsg) {
    for(String line : queryPlan) {
      if(line != null && line.contains(string)) {
        return;
      }
    }
    Assert.fail(errMsg);
  }
this is run 2 times: 1 with PPD on, 1 with off
Also, the queries are such that if we were to push predicate down to an update/delete delta,
the test would produce wrong results
@param enablePPD
@throws Exception
ql/src/test/org/apache/hadoop/hive/ql/TestTxnCommands2.java