An overview of DataNucleus caching can be seen here. As mentioned earlier, DataNucleus provides a simple wrapper to Oracle's Coherence caches. This currently takes the NamedCache interface in Tangosol and instantiates a cache of a user provided name. To enabled this you should set the following properties as input to the PersistenceManagerFactory/EntityManagerFactory

datanucleus.cache.level2=true
datanucleus.cache.level2.type=tangosol
datanucleus.cache.level2.cacheName={tangosol cache name}

The Coherence cache name is the name that you would normally put into a call to CacheFactory.getCache(name). As mentioned earlier, this cache does not support the pin/unpin operations found in the standard JDO 2 interface. However you do have the benefits of Oracle's distributed/serialized caching. If you require more control over the Coherence cache whilst using it with DataNucleus, you can just access the cache directly via

DataStoreCache cache = pmf.getDataStoreCache();
NamedCache tangosolCache = ((TangosolLevel2Cache)cache).getTangosolCache();