How to configure batch/fetch size

[qbacomarch]

Hi,

Recently I wrote a simple application (EJB3.0), which reads all rows of one unrelated table.
My problem is that I want to set batch (or fetch - i don't know which term is appropriate) size. As I look at the session trace in oracle 10g, i get, thath it is fetching the data in 10-row packs (73 rows, 8 fetches) . However, during the deployment, I get this message form JBoss:

INFO [SettingsFactory] JDBC batch size: 15

How can I change that size? It would be great if there is some way to change it for this specific app. I was trying to find out, if there's any way to do this by configuring the persistence.xml, but i couldn't find any docs about it.

[azhurakousky]

Yes you should do it in persistance.xml
Try this:

<persistence>
 . . . . . . . .
 <properties>
 <property name="hibernate.jdbc.batch_size" value="25"/>
 . . . . . . .
 </properties>
 . . . . . . . .
</persistence>

Regards

Oleg Zhurakousky

[qbacomarch]

Well, I tried this, but it didn't work.
Here's my persistence.xml

<?xml version="1.0" encoding="UTF-8"?>
<persistence version="1.0" xmlns="http://java.sun.com/xml/ns/persistence">
 <persistence-unit name="DBTestOne-ejb" transaction-type="JTA">
 <provider>org.hibernate.ejb.HibernatePersistence</provider>
 <jta-data-source>OracleDS</jta-data-source>
 <class>DBTest.EJBTestEntity</class>
 <properties>
 <property name="hibernate.jdbc.batch_size" value="25"/>
 </properties>
 </persistence-unit>
</persistence>

The database logs show, that there are 73 rows in 8 fetches.

Here's the code of the session bean thath queries the database:

@Stateless
public class EJBTestSessionBean implements DBTest.EJBTestSessionRemote {

 @PersistenceContext
 EntityManager em;

 public EJBTestSessionBean() {}

public Collection<EJBTestEntity> getEJBTestEntity(){
 Query query;
 query = em.createQuery("from EJBTestEntity t"); /
 return query.getResultList();
 }
}

[azhurakousky]

Believe me, I hate to say it, but it does work for me here. . .
Do you have any other EJB3 configuration deployed?

Here is what I get:

08:34:54,743 INFO [SettingsFactory] JDBC batch size: 19

and here is my persistance.xml

<?xml version="1.0" encoding="UTF-8"?>
<persistence>
 <persistence-unit name="tempdb">
 <provider>org.hibernate.ejb.HibernatePersistence</provider>
 <jta-data-source>java:/MySqlDS</jta-data-source>
 <properties>
 <property name="hibernate.jdbc.batch_size" value="19"/>
 </properties>
 </persistence-unit>
</persistence>

[qbacomarch]

Finally, I found a solution to this.

The property to set in persistence.xml is "hibernate.jdbc.fetch_size".

Thank You azhurakousky, You were very helpful to me :)

[azhurakousky]

Ahh. . .
So it wasn't a "batch size", but a "fetch_size". Different property, but I am glad you found a way

Oleg