object « Cache « JPA Q&A

1. Hibernate cache for mappedBy object stackoverflow.com

I have code like:

@Entity
@Table(name = "A")
@Cache(usage = CacheConcurrencyStrategy.NONSTRICT_READ_WRITE)
public class A
{
  @OneToOne(cascade={CascadeType.ALL}, fetch=FetchType.EAGER, mappedBy="a")
  public B getB() {};
}

@Entity
@Table(name = "B")
@Cache(usage = CacheConcurrencyStrategy.NONSTRICT_READ_WRITE)
public class B
{
  @OneToOne(cascade={}, fetch=FetchType.LAZY)
  @JoinColumn(name="A_ID")
  ...

2. Object not getting picked from second level cache in hibernate? stackoverflow.com

i specified the below properties in cfg file.

<property name="hibernate.cache.use_second_level_cache">true</property>
<property name="hibernate.cache.provider_class">
     net.sf.ehcache.hibernate.EhCacheProvider</property>

In my main1 program i create the person with id 1 and commited and made ...

3. How to force Hibernate use Object API of EhCache forum.hibernate.org

Hi, I would like to change the default behavior of Hibernate which stores objects in a second-level cache(I configured it to use net.sf.ehcache.hibernate.EhCacheProvider) as a list of serializable attributes rather than plain objects. This results in unnecessary(for my specific purposes) instance creation each time I use Session.get() for the object state already in cache. How can I avoid this situation by ...

4. Objects are not hydrated when using second level cache forum.hibernate.org

5. How to invalidate cached objects ? forum.hibernate.org

I have Department class and Employee class. They are properly mapped as Hibernate objects. Each department has some employees (Set department.getEmployees()). When I call department.getEmployees() from one servlet to return all the employees in the specified department, the same set of objects are returned even after some employee objects are removed from another servlet. So how to invalidate the cached objects ...

6. identity of objects returned from jvm cache forum.hibernate.org

hello, I have a class configured to be cached via jvm / ehcache: Code: now I query the same instance two times, i.e. : Code: Order o1 = session.createQuery(HQL_FIND_ID123) ; Order o2 = session.createQuery(HQL_FIND_ID123); Using the cache I expected that not only o1.equals(o2) but also o1==o2 (because the cache is supposed to return the same instance previously ...

7. Checking if an object is the cache forum.hibernate.org

Hello, We would like to optimize our database query's by only querying for objects that aren't in the cache. So given a list of primary keys, we only want to execute a query on the objects that don't exist in the cache. This way we know that we can execute Session.get() knowing that we will not generate any SQL. It's just ...

8. Retrieving objects from second level cache forum.hibernate.org

Hi, Is is possible to get an object from the second level cache without getting a session (just using the session factory)? In my application, I have some objects loaded in the second level cache (read-only objects), and I want to avoid getting and releasing a database connection just for getting an object that I know is cached in memory. Thank ...

9. CacheEntry object forum.hibernate.org

10. How does Hibernate push/pull objects into EHCache? forum.hibernate.org

11. Second level cache objects getting invalidated forum.hibernate.org

I'm using the EHCache as a second level cache, which is working fine when I store an object, re-loading it several times in different sessions (i.e. multiple requests) uses the cache and avoids the database hit. Which is great. However, if I update the object, it forces the cache to be invalidated and reloads the complete object graph from the database. ...

12. Second-level cache & one-to-one : Objects not uptodate forum.hibernate.org

Newbie Joined: Thu Feb 26, 2004 10:19 am Posts: 8 Location: Passau, Germany Hi to everybody! We use hibernate in a mid-sized project. We use Hibernate 2.1.2 with ehcache as Second-level Cache. I have now two classes mapped by one-to-one: (see attached mapping files) MainObject and Object2, each of them using the second-level cache ("usage=read-write") ..within the application there is a ...

13. How to obtain an object in secundary cache without clonning forum.hibernate.org

...

14. How to determine if an object is cached in the session ? forum.hibernate.org

15. Does Hibernate cache Object[] ? forum.hibernate.org

16. reassociation of cached objects forum.hibernate.org

Hibernate version: 2.1.7 We are trying to determine how a cached object is reassociated to a session and given a proxy and CGLIBLazyInitializer. When cached objects are concurrently accessed, we occasionally have the error: Session was closed, or Session is closed. We have done extensive logging on the sessionImpl object to see its history. The relevant bit is pasted below. The ...

17. Its possible to block the objects of the second level cache? forum.hibernate.org

18. caching of related objects forum.hibernate.org

Im using the process level JCS cache pretty heavily against a very static database that mainly consists of a single common table with a dozen "detail" tables. My understanding is that Hibernate (2.0.2) will maintain a cache for Main, each of the Detail classes and one per collection relationship between Main and Detail. Is there a way to make it dumber ...

19. Cached Object Synchronization forum.hibernate.org

Hi there, I have a query regarding the synchronization of object state with the data in the database. I have a database, which is being used by two applications simulataneously. Lets say, through first application, I query table 'X' and the data is stored in the hibernate object, which is cached and for the subsequent queries the data would be returned ...

20. second level cache and object disassembly forum.hibernate.org

Hi, I am using Hibernate 3.0 with DB2/iSeries. I have a lot of reference data which does not change at all. Due to the bad db design it is not possible to get all information using SQL. Some data have to be calculated by calling RPG programs which do the magic for you :-( (unless you want to rewrite the RPG ...

21. Accessing Cache object forum.hibernate.org

22. Object Caching forum.hibernate.org

Just wanted to confirm I have understood Hibernate right: Author -1--n-> Message Message -n--1> Author So, an author owns multiple messages, but a message can belong to only one author. Now, if I retrieve say 1000 Messages and all 1000 messages belong to the same author, how many Author objects will be created? Am I correct in thinking that only 1 ...

23. typesafe objects and caching forum.hibernate.org

Hi, When the query cache is enabled, are hibernate queries involvin new'd typesafe objects cached? i.e. if i have a query like so select new domain.TopCustomer( member.name, member.purchasePower ) from domain.Member member where member.purchaseHorizon = 3 and member.purchasePower > 2 and i have the query cache enabled and the query set to cacheable, would new'ly created TopCustomer objects also be cached? ...

24. Need for (re)initializing objects when using 2nd-level cache forum.hibernate.org

I have a DAO layer that executes queries using DetachedCriteria. The mapping files have (by default) lazy="true". Hence, the queries formulated using DetachedCriteria have eager fetching enabled so as to fetch, create/initialize the domain objects as soon as the 'find' query is executed. Here is an example of the how a typical DAO implementation looks like (fyi: A Subtest contains a ...

25. Caching Objects forum.hibernate.org

I'm trying to get up the learning curve with Hibernate. My primary goal right now is to get Hibernate to cache objects for me. I'm still pretty unsure of the distinction between the query cache and the second-level cache, but I assume that understanding will come with time and usage. I've got all the mapping done for a Person object, and ...

26. Will cached objects clean up after session.close()? forum.hibernate.org

Hibernate has a multi-level caching architecture. 1) Session cache 2) Secondary Cache - normally defined using ehcache. The secondary cache data normally outlives any individual session. There are two caching uses for the sescond level cache 1) Individual object data. (Note: Stored in the cache as a set of data rather than a full object). 2) A query result set. (Note: ...

27. Hibernate caching objects? forum.hibernate.org

To begin with, I'm sorry if this question has been here before but I didn't find it. I'm a really new Hibernate user, and I have this problem - I execute a query, and get a list of objects. I change some of the objects in the database, possibly by another client. Then, when I execute the query again, Hibernate fetches ...

28. Problem with level 2 cache and versioned objects forum.hibernate.org

Hi all, We are using hibernate 3.2.2 and ehcache 1.3. The cache provider class is net.sf.ehcache.hibernate.SingletonEhCacheProvider. We have a versioned object X that can get updated by concurrent user threads (via ajax calls in the real world). Without the second level cache on all is fine. StaleObjectStateException gets thrown and we can retry the add if appropriate. However, with the level ...

29. Best way to cache an already-existing object? forum.hibernate.org

Hello, I'm using Hibernate 3.0.5 and I am trying to re-use as much code as I can from already-existing software that uses the same database. I simply jarred up the existing tool and am using it as a library. For this new tool, I'm using Hibernate's first-level caching. The existing tool uses Hibernate as well, but in a more complicated way. ...

30. Second level cache not returning same Java objects forum.hibernate.org

I am using Hibernate 3.2 with JPA and using EhCache as a second level cache. Though, second level cache is working, e.g. when I turn the debugging on, I see messages like: [java] 2007-08-01 14:52:54,449 [ReadWriteCache] Caching: com.amazon.otb.model.DataElement#10000 [java] 2007-08-01 14:52:54,449 [ReadWriteCache] Item was already cached: com.amazon.otb.model.DataElement#10000 However, I noticed that the objects that are being returned are not the same. ...

31. How to know if an object is in second level cache? forum.hibernate.org

Hello, I have a simple problem : given a set of identifiers [1,3,98,...], I want to write a function that returns the list of objects that exist with those identifiers in the database. I want also use the second level cache, to only query the db for the non-cached identifiers. For example if i have the set [1,3,8,43,54]. If i know ...

32. Object somtimes from the cache sometimes not forum.hibernate.org

Hi there, I have an odd question. It is not a real problem, because I have a working work-around. But it is something that made me investigate a lot without any result. Here is my problem: I have a many-to-one relationship the is lazyly fetched. Code: @ManyToOne(fetch = FetchType.LAZY, targetEntity = AbstractLibraryQuestion.class, ...

33. Get Object From Hibernate CacheEntry forum.hibernate.org

34. Object caching in Hibernate forum.hibernate.org

Hi folks, I need to query several Databases for certain entities. I now stumbled upon the problem that Hibernate does have so called "L1" cache, that is enabled by default and that therefore multiple requests against my datasources return the same Objects although the some properties (row values) have changed. I cannot control changes to the database since those are performed ...