@After
  public void tearDown() throws Exception {
    DatabaseProduct.reset();
    TestTxnDbUtil.cleanDb(conf);
  }
Verify queries can run against Derby DB.
 As long as Derby doesn't complain, we assume the query is syntactically/semantically correct.
standalone-metastore/metastore-server/src/test/java/org/apache/hadoop/hive/metastore/txn/TestTxnUtils.java