[hibernate-issues] [Hibernate-JIRA] Commented: (HHH-1523) Rebuild fetches from query-cache hits

[jazir malik (JIRA)]

    [ http://opensource.atlassian.com/projects/hibernate/browse/HHH-1523?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=33662#action_33662 ] 

jazir malik commented on HHH-1523:
----------------------------------

Sorry, I did misunderstand the issue - my bad memory.  Obviously the entity is no longer attached to the Session when the exception is thrown.

> Rebuild fetches from query-cache hits
> -------------------------------------
>
>                 Key: HHH-1523
>                 URL: http://opensource.atlassian.com/projects/hibernate/browse/HHH-1523
>             Project: Hibernate Core
>          Issue Type: New Feature
>          Components: caching (L2), core, query-criteria, query-hql, query-sql
>    Affects Versions: 3.0.5, 3.1
>            Reporter: Vikas Sasidharan
>         Attachments: cache_issue.log, QueryCacheIssue.zip
>
>
> I have two domain objects - Employee and Department - and there is a 1:N relationship from Department to Employee. When I join fetch an Employee with its Department, without query cache enabled, it works fine. If I enable query cache for this same query, it bombs with a LazyInitializationException. 
> Notes:
>   1) We get this error only if query cache is enabled.
>   2) We observed the same behaviour on both oscache and ehcache
>   3) Calling Hibernate.initialize() explicitly after firing the HQL seems to work. The initialization does not fire an extra query though (it seems to pick it from the cache).
>   4) Setting "lazy=false" on the "many-to-one" mapping also works. However, it wouldn't be acceptable.
> Hibernate version: 3.0.5 
> Mapping documents: 
> Employee.hbm.xml 
> <hibernate-mapping> 
>     <class name="tavant.platform.test.domain.Employee" 
>         table="CACHE_ISSUE_EMP" lazy="true"  dynamic-update="true" dynamic-insert="true"> 
>         <cache usage="read-write" /> 
>         <id name="id" column="EMP_ID" type="java.lang.Long" 
>        access="field" unsaved-value="null"> 
>             <generator class="increment" /> 
>         </id> 
>         
>         <property name="name" type="string" update="true" 
>             insert="true" column="EMP_NAME"/> 
>         <many-to-one name="department" class="tavant.platform.test.domain.Department" 
>             cascade="none" outer-join="auto" update="true" insert="true" column="DEPARTMENT_ID"/> 
>     </class> 
> </hibernate-mapping> 
>  
> Department.hbm.xml 
> <hibernate-mapping> 
>     <class name="tavant.platform.test.domain.Department" table="CACHE_ISSUE_DEP" 
>         lazy="true"  dynamic-update="true" dynamic-insert="true"> 
>         
>         <cache usage="read-write" /> 
>         <id name="id" column="DEPARTMENT_ID" 
>        type="java.lang.Long" access="field">            
>        <generator class="increment"/> 
>         </id> 
>         <property name="name" type="java.lang.String" 
>             update="false" insert="true" column="NAME"/> 
>         <bag name="employees" lazy="true" 
>             inverse="true" cascade="save-update" access="field"> 
>             <cache usage="read-write"/> 
>             <key column="DEPARTMENT_ID"/> 
>             <one-to-many class="tavant.platform.test.domain.Employee"/> 
>       </bag> 
>     </class> 
> </hibernate-mapping> 
>  
> Code between sessionFactory.openSession() and session.close(): 
>     public Employee getEmployeeWithDepartment(String empName) { 
>         Session session = null; 
>         try { 
>             session = sessionFactory.openSession(); 
>             Employee emp = (Employee) session.createQuery( 
>                             "from Employee e join fetch e.department where e.name = :name") 
>                             .setString("name", empName) 
>                             .setCacheable(true) 
>                             .uniqueResult(); 
>             // If I uncomment the next line, this works (even without 
>             // firing an extra query)! 
>             // Hibernate.initialize(emp.getDepartment()); 
>             return emp; 
>         } finally { 
>             if (session != null) { 
>                 session.close(); 
>             } 
>         } 
>     } 
>         
>         // First load employee and populate cahces 
>         Employee emp = test.getEmployeeWithDepartment(EMPLOYEE_NAME); 
>         System.out.println("Employee : " + emp + ", Employee.Department : " 
>                         + emp.getDepartment()); 
>         
>         // Now try to make use of the cache 
>         emp = test.getEmployeeWithDepartment(EMPLOYEE_NAME); 
>         System.out.println("Employee : " + emp + ", Employee.Department : " 
>                         + emp.getDepartment());        
>  
> Full stack trace of any exception that occurs: 
> org.hibernate.LazyInitializationException: could not initialize proxy - the owning Session was closed
> 	at org.hibernate.proxy.AbstractLazyInitializer.initialize(AbstractLazyInitializer.java:53)
> 	at org.hibernate.proxy.AbstractLazyInitializer.getImplementation(AbstractLazyInitializer.java:84)
> 	at org.hibernate.proxy.CGLIBLazyInitializer.intercept(CGLIBLazyInitializer.java:134)
> 	at tavant.platform.test.domain.Department$$EnhancerByCGLIB$$67b26899.toString(<generated>)
> 	at java.lang.String.valueOf(String.java:2131)
> 	at java.lang.StringBuffer.append(StringBuffer.java:370)
> 	at tavant.platform.test.client.TestPrefetchRelationWithQueryCacheEnabled.main(TestPrefetchRelationWithQueryCacheEnabled.java:116)
>  
> Name and version of the database you are using: 
> We have noticed this on Oracle and HSQL 
> The generated SQL (show_sql=true): 
> #First read, goes fine 
> Hibernate: select employee0_.EMP_ID as EMP1_0_, department1_.DEPARTMENT_ID as DEPARTMENT1_1_, employee0_.EMP_NAME as EMP2_1_0_, employee0_.DEPARTMENT_ID as DEPARTMENT3_1_0_, department1_.NAME as NAME0_1_ from CACHE_ISSUE_EMP employee0_ inner join CACHE_ISSUE_DEP department1_ on employee0_.DEPARTMENT_ID=department1_.DEPARTMENT_ID where (employee0_.EMP_NAME=? ) 
> #Prints the Employee and Department fine 
> Employee : [Id : 1, name : testEmployee], Employee.Department : [Id : 1, name : testDepartment] 
> #Second read bombs! 
> org.hibernate.LazyInitializationException: could not initialize proxy - the owning Session was closed
> 	at org.hibernate.proxy.AbstractLazyInitializer.initialize(AbstractLazyInitializer.java:53)
> 	at org.hibernate.proxy.AbstractLazyInitializer.getImplementation(AbstractLazyInitializer.java:84)
> 	at org.hibernate.proxy.CGLIBLazyInitializer.intercept(CGLIBLazyInitializer.java:134)
> 	[..]
> Please have a look at the post [http://forum.hibernate.org/viewtopic.php?t=955839] for more details and follow ups.
> Kindly help.  I am attaching an Eclipse Project containing the TestCase. The main file is TestPrefetchRelationWithQueryCacheEnabled.
> Thanks,
> Vikas

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