What version of OpenJPA are you using? On Wed, Aug 3, 2011 at 2:59 AM, Michael Pflueger <michael.pflue...@sma.de>wrote:
> Hi, > > Can anyone of you give a hint about traversing huge result sets using > OpenJPA? > > I've tried enabling large/scrolling result sets by setting FetchBatchSize. > However, when I iterate over the result, I need to repeatedly call > entityManager.clear(), because a simple entityManager.detach(object) after > each access is not enough to clean old objects from the heap and thus I get > OutOfMemory erros without the clean(). > > entitymanager.clean() seems to work fine without large result sets > enabled. > With LRS enabled, however, I get a problem during the traversal, because > after a clean() call the iterator delivers an object that openjpa thinks is > managed, but the object contains a lazy one to many relation and I can't > access it, I get a nullpointer exception. I've tried detaching and merging > the object I get from the iterator, but this does not help, openjpa does > neither detach nor merge it properly so I can use the lazy association > again. > > So I'm a bit puzzled about how people traverse large sets of data, and > about why a simple detach of objects is not enough to let the garbace > collector clean them... I have not configured any additional cache. > I could try to provide a simple testcase if one is needed. > > > Regards, > Michael > ___________________________________________________ > > SMA Solar Technology AG > Aufsichtsrat: Guenther Cramer (Vorsitzender) > Vorstand: Juergen Dolle, Roland Grebe, Uwe Hertel, Pierre-Pascal Urbon, > Marko Werner > Handelsregister: Amtsgericht Kassel HRB 3972 > Sitz der Gesellschaft: 34266 Niestetal > USt-ID-Nr. DE 113 08 59 54 > WEEE-Reg.-Nr. DE 95881150 > ___________________________________________________ > -- *Rick Curtis*
