Enthuware

Hi All !

I have passed today 1Z0-898 (Java EE 6 Java Persistence API Developer Certified Expert Exam) with 91%

My study was as follows:
1. Read completely "Pro JPA 2: mastering the Java Persistence API" by Mike Keith, Merrick Schincariol. Pro JPA 2.0 is very well written, highly recommended.
2. Completed all four tests in Enthuware's JPAD 6.
3. Read completely JPA 2.0 specification. JPA 2.0 specification is a Bible for this exam - must read. (http://jcp.org/aboutJava/communityproce ... index.html)
4. Read second time Pro JPA 2.0.
5. Completed again all four tests from JPAD 6. Important: make sure you read all explanations from Enthuware's JPAD 6 - it has questions similar to ones you will get on the exam. All simulator's questions are relevant to the exam.

On the second run of JPAD 6 my results were: 70%, 67%, 70%, 77%. So, you can see simulator's questions are bit more complicated than real questions.

Good luck,
Mikalai Zaikin

Some random tips for test takers:
1. Persistence context lifecycle (transaction scoped vs extended)
2. Entity Manager types (container mananed vs application manaed)
3. Criteria queries typed/untyped (multiselect); subquery - how to get max value in subquery and compare with attribure in main query; how many Roots may exist in query (1...n).
4. PersistenceException subclasses - know them by heart! Which rollbacks whole transaction/rollback only current statement
5. Locking optimistic/pessimisic. Know by heart all LockModeType values and what they provide.
6. Transaction attributes inheritance - single question, EJB 3.1, section 13.3.7.1
7. Entity inheritance strategies (JOINED, SINGLE_TABLE)
8. Embeddables collections (@ElementCollection, @CollectionTable)
9. @Version and bulk updates - what possible problems might occure.
10. Second level caching: shared cache mode ENABLE_SELECTED (what will be cached and what will not be cached with different @Cacheable)
11. javax.persistence.Cache.evict(class) - what it does to subclasses
12. PersistenceUtil.isLoaded() for regular one-to-one relationship and one-to-one relationship with LAZY fetch type
13. Pessimistic lock - escalation from read to write when writing to DB.
14. JPQL functions SIZE(), COUNT() - make sure you know what they do and in what part of query they may be used

15. How to add managed classes to Persistent Unit (add to persistence.xml OR orm.xml). Remember that within container (EAR, WAR, EJB-JAR) managed classes discovered automatically.
16. What object is used to create TypedQuery?
17. Multiple Persistent Units in EAR. How can entities access each other (and when they cannot)? Can Persistence Units within EAR have same names?
18. UserTransaction. What methods when can throw which exceptions.

19. Know all TransactionAttributeType.* and what they mean
20. Know @OrderColumn - how it works
21. Know @AttributeOverrride syntax and how it works

22. What options provides JPA for composite primary keys (@EmbeddedId, @IdClass)? What is the difference?
23. Entity lifecycle (removed, detached, managed, merged, and how can change one state to another)
24. Canonical Metamodel Classes: how fields look like in them (single property, collection property, list property,...)?
25. Know what mappedBy and targetEntity used for.

Congratulations and thanks a lot for the detailed feedback!