Hi.

Considering the following example, I'm not sure second level cache is working :

...
Session session1 = sessionFactory.openSession();
Session session2 = sessionFactory.openSession();

Long id = new Long(1);
MyObject obj1 = (MyObject) session1.get(MyObject.class, id);
MyObject obj2 = (MyObject) session2.get(MyObject.class, id);
...

each session returns an object.
But using
hibernate.cache.use_query_cache=true

I can see 2 sql request.
I hoppend that second level cache (jvm) will allow the second request to not occur.

I tried with HashtableCache and EHCache on hibernate 2.1.2

I tried many ways
- with and without closing session1 before using session2,
- with and witjout transactions,
- with and without hibernate.cache.use_query_cache=true (Also, it seems that we MUST use it. Isn't it optionnal ?)

By the way, I saw that the result is different if I provide my own connections to the session. When I do this, they are timestamps that are always <0 (Generated by class Timestamper ...). Well, I'm not sure it's a problem ...

Thanks in advance for any help.

Mike

How about your mapping files? Do they decalare that this object should be cached?

eg:
<cache usage="read-only"/>
In the mapping file for "MyObject"


James

sorry, I forgot to say that I already have put this line in my mapping ...

and it don't works ...

(I'm not sure my previous post was really clear ...)

just a bit of a guess- I'm using sess.load, not sess.get. Possibly hibernate doesn't look in cache on get?

I tried get and load.
load is used to return a proxy if possible.

In your case, do you have cache ?
On session, cache works very well : 2 get with the same id on the same session returns the same object and execute only one sql query.
But do you see that the samething on 2 different sessions is true ???
(At least, it must run just one query but it seems that it will not return the same object instance ...)

It finally works by changing



to



ie opening the second session AFTER the object was put in jvm cache.

I have another problem :

If I change the working example, opening sessions with

Session session2 = sessionFactory.openSession(c);
..
Session session1 = sessionFactory.openSession(c);

(I provide a connection)

It stop working.