@Override
  public DatabaseMetaData getMetaData() throws SQLException {
    if (isClosed) {
      throw new SQLException("Cannot create statement because connection is closed");
    }
    if (getSqlDialect().equals(Constant.TABLE_DIALECT)) {
      return new IoTDBRelationalDatabaseMetadata(this, getClient(), sessionId, zoneId);
    }
    return new IoTDBDatabaseMetadata(this, getClient(), sessionId, zoneId);
  }
ConnectionTimeout and SocketTimeout. Unit: ms. If not set, default value 0 will be used, which
means that there's no timeout in the client side.
iotdb-client/jdbc/src/main/java/org/apache/iotdb/jdbc/IoTDBConnection.java