Re: [Springframework-developer] Batch processing with hibernate

[Juergen H. <ju...@in...>]

Why couldn't you use HibernateTransactionManager in combination with =
such
data access code based on HibernateTemplate?

HibernateTransactionManager doesn't do much more than open a Session, =
start
a transaction - and eventually commit the transaction and close the =
Session.
You can do any number of flush or clear calls inbetween...

Of course, if there's anything specific we can offer in
HibernateTransactionManager to better support such batch-style data =
access,
we are certainly open to it.

Juergen
=20

-----Original Message-----
From: spr...@li...
[mailto:spr...@li...] On Behalf =
Of
Meyer, Stefan
Sent: Tuesday, March 28, 2006 12:57 PM
To: spr...@li...
Subject: [Springframework-developer] Batch processing with hibernate

Hi,

We need batch processing support for hibernate. The processing should =
take
place in one transaction and the list of processed entities must be =
selected
with "select ... For update". HibernateTransactionManager does not =
support
this. The reason is presumably that the first-level cache does not =
support
rollbacks. I think that it is possible nevertheless if you follow the
following rules:

1. flush before setting a savepoint
2. clear the session before rolling back to a savepoint

The consequences of the second point are usually not a problem in batch
processing. Consider the recommended approach:

--------------  hibernate.org

Session session =3D sessionFactory.openSession(); Transaction tx =3D
session.beginTransaction();
  =20
ScrollableResults customers =3D session.getNamedQuery("GetCustomers")
    .setCacheMode(CacheMode.IGNORE)
    .scroll(ScrollMode.FORWARD_ONLY);
int count=3D0;
while ( customers.next() ) {
    Customer customer =3D (Customer) customers.get(0);
    customer.updateStuff(...);
    if ( ++count % 20 =3D=3D 0 ) {
        //flush a batch of updates and release memory:
        session.flush();
        session.clear();
    }
}
  =20
tx.commit();
session.close();

-------------

Clearing the session after or before processing an entity returned from =
the
cursor will only result in slower performance  when loading certain
entities.

We have implemented this kind of batch processing but support by
hibernateTransactionManager would make our life a lot easier.



--
Stefan Meyer
Entwicklung

s....@s2...
T: +49.40.80 81 69-347

SinnerSchrader Neue Informatik
>> Software. Design. Interfaces.
http://www.s2neueinformatik.de/
 =20


-------------------------------------------------------
This SF.Net email is sponsored by xPML, a groundbreaking scripting =
language
that extends applications into web and mobile media. Attend the live =
webcast
and join the prime developer group breaking into this new coding =
territory!
http://sel.as-us.falkag.net/sel?cmd=3Dk&kid=110944&bid$1720&dat=121642
_______________________________________________
Springframework-developer mailing list
Spr...@li...
https://lists.sourceforge.net/lists/listinfo/springframework-developer