Hi!
I use Hibernate 3.3.1 with JPA/EJB3/Glassfish/JBoss Cache. There was an idea than making read only method of stateless session bean (for example findById(...)) annotated by @NotSupported or @Supports will make it faster than with default transaction attribute @Requires.
Surprisingly, annotating method with @NotSupported made its execution much slower (1500 msec vs 120 ms)!
I tried to disable second level cache (JBoss cache), it doesn't help.
Profiling my application I found that method findById() have several hundreds of calls to JoinableCMTTransaction.isTransactionInProgress() method that slows up the execution of method.
Also I add
<property name="hibernate.transaction.manager_lookup_class" value="org.hibernate.transaction.SunONETransactionManagerLookup"/>
to my persistence.xml, it doesn't help too.

Code:
@Stateless
public class CompanyServiceBean implements CompanyService {
...
@PersistenceContext
private EntityManager em;
...
@TransactionAttribute(TransactionAttributeType.NOT_SUPPORTED)
public Company findWithNotSupported(Long id) {
Company res = em.find(Company.class, id); // executes 1500 ms
return res;
}
...
@TransactionAttribute(TransactionAttributeType.REQUIRES)
public Company findWithRequires(Long id) {
Company res = em.find(Company.class, id); // executes 120 ms
return res;
}
...

What can be wrong in my application?