R: Slow performance updating CLOB data

Here a snippet:

        Properties props = new Properties();

        props.put("user", "test1");

        props.put("password", "test1");

        Connection connection = java.sql.DriverManager.getConnection("jdbc:postgresql://<server>", props);

        Statement st = connection.createStatement();

        st.execute("CREATE TABLE TestClob1 (id int8 NOT NULL, data TEXT, PRIMARY KEY(id))");

        st.close();

        st = connection.createStatement();

        st.execute("INSERT INTO TestClob1 (id) VALUES (1) ");

        st.close();

        st = connection.createStatement(ResultSet.TYPE_FORWARD_ONLY, ResultSet.CONCUR_UPDATABLE);

        ResultSet resultSet = st.executeQuery("SELECT id, data FROM TestClob1 WHERE id = 1 ");

        resultSet.next();

        resultSet.updateCharacterStream(2, new StringReader("hello"), "hello".length());

        resultSet.updateRow();

        resultSet.close();