Hi,

I wanted to present some cache feature ideas I had to present them here before putting them in JIRA, so if they are easily rejected I don't have to waste Gavin's time to reject them. ;-)

1) Method Query.setCacheable(Class) or Query.setSecondLevelCacheable(Class).

If a given Object of type Class were loaded in a query, it would be added to second level cache so that it could be loaded by id. (Class would have to be a mapped class registered w/hibernate)

2) Method Criteria.setCacheable(true)

Would work like QueryCache allowing a Criteria query to be cacheable.

3) A way to add objects to cache dynamically. Thus, say I have an Object that I want to load by SQL for some reason. I load it, I want to cache it using the same cache mechanism as the rest of the app. etc. (i.e. Session.getCacheManager().add(Object))

Is there something I am not understanding about caching theory that prevents these from being added?

Thanks

Sorry I about #1 I see from another JIRA issue that this already happens. Head still swirling about what exactly happens when with cache ;)

#1 I don't quite undertand
#2 exists for a while now
#3 is interesting - currently native SQL queries are cacheable, so why not just use that?

Sorry #2 is the one I realized existed.

#1 basically would cache the result sets of criteria queries like the result set of HQL queries.

Thus, if you did:

session.createCriteria(MyClass.class)
.add(Expression.eq("state", "NY"))
...
You would be able to cache the result set of this to not have to query the db everytime this criteria query were made.

#3 basically would allow Hibernate to cache either objects not loaded with hibernate (say loaded from XML). I was thinking it would also be good for caching objects created like:
select new SimpleCatData(cat.id, cat.name, count(kitten)) from cat as Cat
outer join cat.kittens as kitten.

but that can be done using cacheable queries I assume.

I understand #3. I still have absolutely no idea what the other thing you are asking for is.

A month later...

The idea is this. Say you had a Cat object. In my understanding of Hibernate the following two actions are equivalent:



and



However, in the below code, it is possible to add setCacheable(true) before list thus caching the result set. In the above code it is not.

Of course it is, there is Criteria.setCachable(true). Please read the API.

Wow... duh. Can't believe I missed that one. Sorry about that.