You may also want to check out the recent discussion on performance...
http://n2.nabble.com/slow-performance-on-MySql-5.0-td782401.html#a782547
Kevin
On Fri, Sep 5, 2008 at 1:48 PM, pauldeg <[EMAIL PROTECTED]> wrote:
>
> I am not actually counting start up costs, since I invoke StopWatch.start()
> _after_ EntityManagerFactory and EntityManager is initialized.
>
>
>
>
> Craig L Russell wrote:
> >
> > Hi,
> >
> > I think your test is probably dominated by startup costs. Initializing
> > the EntityManagerFactory involves much more than getting a JDBC
> > connection from the DriverManager.
> >
> > If your application typically starts a VM and inserts two objects,
> > then your example is probably fair.
> >
> > If your application does more work, it might be good to try to model
> > the entire workload.
> >
> > Regards,
> >
> > Craig
> >
> > On Sep 5, 2008, at 10:09 AM, paul_deg wrote:
> >
> >> I was thinking to switch to OpenJPA from Spring JDBC, just recently
> >> run
> >> a very simple test with 2 classes, SQL insert basically, the
> >> difference
> >> between plain JDBC and OpenJPA is more than 7 times!
> >> Why such poor performance? Below is my sample code and results, I used
> >> Enhancer as JVM argument, actually without it JPA result was almost
> >> twice faster!
> >>
> >> public static void main(String[] args) {
> >>
> >>
> >> Bill bill = new Bill();
> >> int id = new JVMRandom().nextInt(Integer.MAX_VALUE);
> >> bill.setId(id);
> >> bill.setCreated(new Date());
> >> bill.setPurchaseid(501253634);
> >> bill.setStatus(1);
> >>
> >> // System.out.println("bill id=" + id);
> >>
> >> Product prod = new Product();
> >> prod.setId(1);
> >>
> >> BillProduct bp = new BillProduct();
> >> bp.setBillid(bill);
> >> bp.setId(new JVMRandom().nextInt(Integer.MAX_VALUE));
> >> bp.setProductid(prod);
> >>
> >> StopWatch sw = new StopWatch();
> >>
> >> try {
> >> Class.forName("org.postgresql.Driver");
> >>
> >> String url =
> >> "jdbc:postgresql://localhost/mydb?user=admin&password=admin";
> >> Connection conn = DriverManager.getConnection(url);
> >> conn.setAutoCommit(false);
> >>
> >> // System.out.println("bill id=" + id);
> >> sw.start();
> >>
> >> PreparedStatement pstm = conn
> >> .prepareStatement("insert into bill(id, status,
> >> purchaseid, created) values (?, ?, ?, ?)");
> >> pstm.setInt(1, bill.getId());
> >> pstm.setInt(2, bill.getStatus());
> >> pstm.setInt(3, 501253634);
> >> pstm.setDate(4, new
> >> java.sql.Date(System.currentTimeMillis()));
> >> pstm.executeUpdate();
> >> pstm.close();
> >>
> >> pstm = conn
> >> .prepareStatement("insert into bill_product(id,
> >> productid, billid) values (?, ?, ?)");
> >> pstm.setInt(1, new JVMRandom().nextInt(Integer.MAX_VALUE));
> >> pstm.setInt(2, 1);
> >> pstm.setInt(3, bill.getId());
> >> pstm.executeUpdate();
> >> pstm.close();
> >>
> >> conn.commit();
> >> sw.stop();
> >>
> >> System.out.println("jdbc time=" + sw.getTime());
> >> conn.close();
> >>
> >> } catch (Exception e) {
> >> // TODO Auto-generated catch block
> >> e.printStackTrace();
> >> }
> >>
> >> sw.reset();
> >>
> >>
> >> //openjpa
> >> id = new JVMRandom().nextInt(Integer.MAX_VALUE);
> >> bill.setId(id);
> >> bp.setId(new JVMRandom().nextInt(Integer.MAX_VALUE));
> >>
> >> // persist
> >> EntityManagerFactory emf = Persistence
> >> .createEntityManagerFactory("testjpa");
> >> EntityManager em = emf.createEntityManager();
> >>
> >> sw.start();
> >>
> >> em.getTransaction().begin();
> >>
> >> em.persist(bill);
> >> em.flush();
> >> em.persist(bp);
> >>
> >> em.getTransaction().commit();
> >>
> >> sw.stop();
> >> System.out.println("openjpa time=" + sw.getTime());
> >>
> >> em.close();
> >>
> >> }
> >>
> >>
> >>
> >> *Console output: *
> >>
> >> jdbc time=78
> >> 93 testjpa INFO [main] openjpa.Runtime - Starting OpenJPA 1.2.0
> >> 203 testjpa INFO [main] openjpa.jdbc.JDBC - Using dictionary class
> >> "org.apache.openjpa.jdbc.sql.PostgresDictionary".
> >> openjpa time=547
> >>
> >>
> >>
> >
> > Craig L Russell
> > Architect, Sun Java Enterprise System http://java.sun.com/products/jdo
> > 408 276-5638 mailto:[EMAIL PROTECTED]
> > P.S. A good JDO? O, Gasp!
> >
> >
> >
> >
>
> --
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> http://n2.nabble.com/poor-performance-tp841672p841878.html
> Sent from the OpenJPA Users mailing list archive at Nabble.com.
>
>
