@Test
  public final void testCreateAndPurgeExternalTableByExecuteQuery()
      throws IOException, ServiceException {
    TajoConf conf = cluster.getConfiguration();
    final String tableName = "testCreateAndPurgeExternalTableByExecuteQuery";

    Path tablePath = writeTmpTable(tableName);
    assertFalse(client.existTable(tableName));

    String sql =
        "create external table "
            + tableName
            + " (deptname text, score int4) "
            + "using csv location '"
            + tablePath
            + "'";

    client.executeQueryAndGetResult(sql);
    assertTrue(client.existTable(tableName));

    client.updateQuery("drop table " + tableName + " purge");
    assertFalse(client.existTable(tableName));
    FileSystem localFS = FileSystem.getLocal(conf);
    assertFalse(localFS.exists(tablePath));
  }
  @Test
  public final void testDDLByExecuteQuery() throws IOException, ServiceException {
    final String tableName = "testDDLByExecuteQuery";
    Path tablePath = writeTmpTable(tableName);

    assertFalse(client.existTable(tableName));
    String sql =
        "create external table "
            + tableName
            + " (deptname text, score int4) "
            + "using csv location '"
            + tablePath
            + "'";
    client.executeQueryAndGetResult(sql);
    assertTrue(client.existTable(tableName));
  }