I am learning second level cache, It didn't work properly. Can anyone explain this please.

Session session = HibernateUtil.getSessionFactory().getCurrentSession();
session.beginTransaction();
C c1 = new C();
c1.setName("c1");
session.saveOrUpdate(c1);
session.getTransaction().commit();

session = HibernateUtil.getSessionFactory().getCurrentSession();
session.beginTransaction();
C test = (C)session.get(C.class, c1.getId()); // I expected to get this object from second level cache. But hibernate does a select a select.
// Hibernate did ask the second level cache for this id before the select but second level cache didn't have it
session.getTransaction().commit();

session = HibernateUtil.getSessionFactory().getCurrentSession();
session.beginTransaction();
test = (C)session.get(C.class, c1.getId()); // Now second level cache returns the object
session.getTransaction().commit();

This is the mapping file.

<class name="C" table="TABLE_C" >
<cache usage="read-write"/>
<id name="id" column="C_ID">
<generator class="native" />
</id>
<property name="name" />
</class>

I thought Hibernate would put the result of insert into the second level cache. But It didn't

I have done some debugging and I can simplify my question.



But at the end of this transaction, second level cache doesn't have c1 stored.

However If I use assigned primary key as below where the insertion can wait until I call commit, second level cache stores the c1.

It is only objects that are inserted into the immediately into the database are not going to the second cache.
If I do an update immediately after the insert, the object gets stored into the second level cache.
(I inserted the line highlighted by bold and it get stored into the second level cache)

Session session = HibernateUtil.getSessionFactory().getCurrentSession();
session.beginTransaction();
C c1 = new C();
c1.setName("c1");
session.saveOrUpdate(c1);// This one need an immediate insert in order to get the Id assigned

c1.setName("change it and see if you are getting stored into second level cache");

session.getTransaction().commit();

After that, just to see what happens if I force update to happen immediately,I did a session.flush() after the bold line. Again the object is available in second level cache.(so my next doubt here is hibernate should use memory locks here)

It is only the object that need an immediate sql insert are not going to the second level cache.

Can someone clear this please?