JPA query cache

[whelan]

Hi

I have tried to add query and entity cache to my queries on JBoss 7.1.1 and EAP 6.1 and EAP 6.2.

Entity cache works fine by following the guidelines.

Query cache is another matter. I have tried different scenarios, but the query will not be hit.  Need to get to my other computer at work.

Added this to persistence.xml

<persistence-unit name="cache_persistence">

  <provider>org.hibernate.ejb.HibernatePersistence</provider>

  <jta-data-source>java:jboss/datasources/cache</jta-data-source>

  <class>com.unwire.cache.model.CacheTest</class>

  <shared-cache-mode>ENABLE_SELECTIVE</shared-cache-mode>

  <properties>

         <property name="hibernate.show_sql" value="false" />

         <property name="hibernate.hbm2ddl.auto" value="none" />

   <property name="hibernate.cache.use_second_level_cache" value="true"/>

   <property name="hibernate.cache.use_query_cache" value="true"/>

   <property name="hibernate.generate_statistics" value="true"/>

   </properties>

</persistence-unit>

I'm also using the query hints mentioned in this post:

Re: Query result caching

Query hints:

• javax.persistence.cache.retrieveMode : CacheRetrieveMode
  • BYPASS : Ignore the cache, and build the object directly from the database result.
  • USE : Allow the query to use the cache. If the object/data is already in the cache, the cached object/data will be used.
• javax.persistence.cache.storeMode : CacheStoreMode
  • BYPASS : Do not cache the database results.
  • REFRESH : If the object/data is already in the cache, then refresh/replace it with the database results.
  • USE : Cache the objects/data returned from the query.

With USE for both

I'm using default standalone.xml with only added this datasource. Which configuration is missing?

[smarlow]

From the Hibernate documentation:

So by default, individual queries are not cached even after enabling query caching. To enable results caching for a particular query, call org.hibernate.Query.setCacheable(true)

Also read related questions about the query cache which explains some of the reasons for enabling the query cache.  The Hibernate doc link above should also help explain the same.

[whelan]

But that means that this can not be done with the normal JPA 2.0 given by JEE 6?

Using JPA I use the entityManager and not a hibernate session.

How can I get access to the hibernate session through JPA 2.0?

[kazaag]

You can activate implementation dependent feature with hints (setHint() on JPA query or via @NamedQueryHint annotation for name query). For hint for Hibernate (for the query) can be found here: Chapter 3. Working with objects

PS: it is easy to get the unerling implementation class: http://stackoverflow.com/questions/4148231/how-can-i-get-the-session-object-if-i-have-the-entitymanager

[whelan]

Hi François

Found the issue from the great links you have provided. Found out that I need to set the cacheMode in the queryHint. Had the cacheable but added the cacheMode:

        query.setHint("org.hibernate.cacheable", true);

        query.setHint("org.hibernate.cacheMode", "NORMAL");

Very much thank you for the help. I didn't need to go through the hibernate session