PI19732: FIRST JPQL WITH LEFT JOIN FETCH FOR LAZY LOADED SPECIFIED AND DATA CACHE ENABLED. SUBSEQUENT DOES NOT GET LOADED.

8.5.5.5: WebSphere Application Server V8.5.5 Fix Pack 5
8.5.5.6: WebSphere Application Server V8.5.5 Fix Pack 6
8.5.5.7: WebSphere Application Server V8.5.5 Fix Pack 7
8.5.5.8: WebSphere Application Server V8.5.5 Fix Pack 8
8.5.5.9: WebSphere Application Server V8.5.5 Fix Pack 9
8.5.5.10: WebSphere Application Server V8.5.5 Fix Pack 10
8.5.5.11: WebSphere Application Server V8.5.5 Fix Pack 11
8.5.5.12: WebSphere Application Server V8.5.5 Fix Pack 12
8.5.5.13: WebSphere Application Server V8.5.5 Fix Pack 13
8.5.5.14: WebSphere Application Server V8.5.5 Fix Pack 14
8.5.5.15: WebSphere Application Server V8.5.5 Fix Pack 15
8.5.5.14: WebSphere Application Server V8.5.5 Fix Pack 14
8.5.5.17: WebSphere Application Server V8.5.5 Fix Pack 17
8.5.5.20: WebSphere Application Server V8.5.5.20
8.5.5.18: WebSphere Application Server V8.5.5 Fix Pack 18
8.5.5.19: WebSphere Application Server V8.5.5 Fix Pack 19
8.5.5.16: WebSphere Application Server V8.5.5 Fix Pack 16
8.5.5.21: WebSphere Application Server V8.5.5.21

APAR status

• Closed as program error.

Error description

• OPEN JPA JIRA  OPENJPA-2508:
  
  In a simple JPQL with left join fetch for a lazy loaded
  association specified and data cached enabled, first time the
  query executed, the lazy loaded association get loaded,
  returned and cached. Subsequent invocation of the same query
  does NOT "load" and return the association from the query
  invocation.
  
  The test case call doQuery() twice, i.e. same call path. The
  first call executes the SQLs and fetches Dept and Employee from
  the db. Both dept and employee were cached. The second call the
  Employee was fetched from cache but the Employee.dept remains
  null even the SQL requests to load dept using "join fetch dept".
  
  The attached test will pass (Employee.dept is loaded; not null)
  if either:
  1) the Employee.dept is marked FetchType.EAGER, or
  2) TestNPE2.doquery().... em.detach(emp) is removed.
  

Local fix

• N/A
  

Problem summary

• ****************************************************************
  * USERS AFFECTED:  All users of IBM WebSphere Application      *
  *                  Server V8.5.0 and V8.5.5 who make use of    *
  *                  JPA Criteria and OpenJPA QueryCache.        *
  ****************************************************************
  * PROBLEM DESCRIPTION: When a JPQL with 'LEFT JOIN FETCH' is   *
  *                      run and OpenJPA DataCache is enabled,   *
  *                      incorrect results are returned.         *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  When the OpenJPA DataCache is enabled (that is,
  openjpa.DataCache=true), there exists an issue where
  association data for a JPA entity is not loaded when
  performing left fetch joins.  To illustrate this issue lets
  look at snippets of sample code.  Take this JUnit test where
  Department entity has a OneToMany relationship with the
  Employee entity:
  private void doQuery(EntityManagerFactory emf) {
  String query = "select o from Employee o " + "left
  join fetch o.dept " + "where o.dept.deptno = 10";
  EntityManager em = emf.createEntityManager();
  List<Employee> emps = em.createQuery(query,
  Employee.class).getResultList();
  //There are 4 employees and 2 departments in the
  database, 2 employees per department.
  Assert.assertEquals(4, emps.size());
  for (Employee emp : emps) {
  em.detach(emp);
  Assert.assertNotNull(emp.getDept());
  Assert.assertEquals(2,
  emp.getDept().getEmployees().size());
  }
  em.close();
  }
  With this test, the first run works fine.  Notice that
  'left join fetch' is used in the query.  The first time this
  test is run the associations get loaded, returned, and
  cached (since DataCache is enabled).  When the test is called
  a second time (under the same EntityManagerFactory), query
  does not return the Department association
  

Problem conclusion

• With this fix, code has been added to OpenJPA to ensure the
  proper results are returned from a JPQL query with 'LEFT JOIN
  FETCH' and OpenJPA DataCache is enabled.
  
  The fix for this APAR is currently targeted for inclusion in
  Service Level (Fix Pack) 8.5.5.5 of WebSphere Application
  Server version 8.5.5.
  
  Please refer to the recommended updates page for delivery
  information:
  http://www.ibm.com/support/docview.wss?rs=180&uid=swg27004980
  

Temporary fix

Comments

APAR Information

• APAR is sysrouted FROM one or more of the following:

• APAR is sysrouted TO one or more of the following:

Fix information

• Fixed component name

  WEBSPHERE APP S

• Fixed component ID

  5724J0800

Applicable component levels

• R850 PSY

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