Can I configure Hibernate NOT to use any second level cache?

oliver.kuntze · **Joined:** Wed Dec 08, 2004 9:17 am **Posts:** 25

The net.sf.hibernate.cfg.Environment doc reads that JCS is assumed for 2nd level caching (though the readme in the distribution says "deprecated").
So I am questioning myself if I can configure hibernate not to use any 2nd level cache or if I have to call "evict()" on all objects that are not served by a cascading "evict()"?
Any help would be greatly appreciated.
Thanks a lot!

Oliver

christian · **Posted:** Wed Dec 08, 2004 11:44 am

Read the chapter in the reference documentation about Caching.

oliver.kuntze · **Joined:** Wed Dec 08, 2004 9:17 am **Posts:** 25

Hi Christian,

already did that. The only extra info that I get is that EHCache replaced JCS as the default cache.
So, if there is a default cache that implies that 2nd level caching is "on". Excuse me, if I am too blind to find the part about switching it "off".
Do I interpret your answer correctly that there is no way to configure hibernate NOT to use 2nd level caching?

Thanks,

Oliver

michael · **Posted:** Wed Dec 08, 2004 11:56 am

If you don't add any cache tags to your mappings, nothing is cached.

anthony · **Posted:** Wed Dec 08, 2004 11:58 am

you have nothing to do.
if you don't configure second level caching at class level, no cache will be used.

read the chapter again

Quote:

It is possible to configure a cluster or JVM-level (SessionFactory-level) cache on a class-by-class and collection-by-collection basis

Code:

<cache 
    usage="transactional|read-write|nonstrict-read-write|read-only"  (1)
/>

that is to say: if you don't do this, no cache will be used...

anthony · **Posted:** Wed Dec 08, 2004 12:00 pm

oups, Michael is faster

oliver.kuntze · **Joined:** Wed Dec 08, 2004 9:17 am **Posts:** 25

Thank you guys for the prompt answers!

I am comparing a possible hibernate data access layer against our current JDO data access layer. We have the requirement, that most of the time our persistent object graphs are managed by a persistence manager that uses 2nd level caching but in certain situations object graphs containing objects of the same classes have to be processed by a cacheless persistence manager. In JDO we just use a different persistence manager factory. It seems that with hibernate I can only switch caching on and off using the mappings. Since there is only one mapping per class it seems not possible for example to switch from a "cacheful" session factory to a "cacheless" factory. Objects are always cached or not cached, I can only supress caching by calling "evict()". Did I get it right, this time? ;-)

Cheers,

Oliver

christian · **Posted:** Wed Dec 08, 2004 12:21 pm

You can have two SessionFactories with a cache/cacheless configuration. Usually you don't put the <cache> elements in your mapping files, but bundle them in your hibernate.cfg.xml for all classes and associations. Which is nice, because one hibernate.cfg.xml is for one SessionFactory.

oliver.kuntze · **Joined:** Wed Dec 08, 2004 9:17 am **Posts:** 25

Ahhh, perfect! Will try it out right away...

Thanks a lot!

Oliver