@After
    public void tearDown() throws Exception {
        try {
            if (d != null) {
                dropTables();
                runStatementOnDriver("drop database if exists " + database_with_default_table_type +" cascade");
                runStatementOnDriver("drop database if exists " + default_db + " cascade");
                d.close();
                d.destroy();
                d = null;
            }
        } finally {
            FileUtils.deleteDirectory(wh);
            FileUtils.deleteDirectory(ext_wh);
        }
    }
this is to test different types of Acid tables
itests/hive-unit/src/test/java/org/apache/hadoop/hive/ql/TestDatabaseTableDefault.java