Problemas com HSQLDB

import java.sql.*;
import java.util.Date;

public class MyTest {

    Connection conn;

	public MyTest(String db_prefix) throws Exception {
        Class.forName("org.hsqldb.jdbcDriver");
        conn = DriverManager.getConnection("jdbc:hsqldb:" + db_prefix, "sa", "");
    }

    public void shutdown() throws SQLException {
        conn.close();
    }

    public synchronized void query(String expression) throws SQLException {
        Statement st = null;
        ResultSet rs = null;
        st = conn.createStatement();
        rs = st.executeQuery( expression );
        dump(rs);
        st.close();
    }

    public synchronized void update(String expression) throws SQLException {
        Statement st = null;
        st = conn.createStatement();
        int i = st.executeUpdate(expression);
        if (i == -1) {
            System.out.println("db error : " + expression);
        }
        st.close();
    }

    public static void dump(ResultSet rs) throws SQLException {
        ResultSetMetaData meta   = rs.getMetaData();
        int               colmax = meta.getColumnCount();
        int               i;
        Object            o       = null;
        for(int j=1; j<=colmax; j++ ) {
			System.out.print(meta.getColumnName(j)+" 	");
		}
		System.out.println(" ");
        while( rs.next() ) {
            for (i = 0; i < colmax; ++i) {
                o = rs.getObject(i + 1);
                System.out.print(o==null ? "" : o.toString() + " ");
            }
            System.out.println(" ");
        }
    }

    public static void main(String[] args) {
        MyTest db = null;
        try {
            db = new MyTest("MyTest");
        } catch (Exception ex1) {
            ex1.printStackTrace();
            return;
        }
        try {
            db.query("CREATE TEXT TABLE pessoa ( id INTEGER IDENTITY, nome VARCHAR(50), idade INTEGER, data_nasc DATE)");
            db.query("SET TABLE pessoa SOURCE "pessoa.csv"");
        } catch (SQLException ex2) {
            ex2.printStackTrace();  // second time we run program
        }
        try {
            db.update("INSERT INTO pessoa(nome,idade,data_nasc) VALUES('Daniel', 24, '12-07-1979')");
            db.update("INSERT INTO pessoa(nome,idade,data_nasc) VALUES('Marcelo', 23, null)");

            db.query("SELECT * FROM pessoa"); //WHERE idade > 20");
        } catch (SQLException ex3) {
            ex3.printStackTrace();
        } finally {
			if( db != null ) try { db.shutdown(); } catch( Exception ex ) {}
		}
    }
}