Sorry I can't get your point about Optimistic Locking. If I do some insert inside a transaction that is at least with isolation level "read committed" I don't have any kind of problem with versioning.
Can you please give me an example of how can I have such a problem ?? Thx. On May 18, 9:09 pm, datanucleus <andy_jeffer...@yahoo.com> wrote: > Define your class first, since without a context there is no point to > this. > > JPA uses optimistic txns *only* and so nothing should go in the > datastore before flush(). Nothing. Any implementation that does put > something in the datastore before then is actually problematic since > it can cause optimistic versioning problems. An object being > attributed in the datastore (which is what IDENTITY GeneratedValue > type is) cannot have an identity *value* until it is flushed since it > isn't *persistent* until then. And while you're at it you can run > DataNucleus against H2. > > You should not have the guarantee to view the identity of a not-yet- > persistent object until it is persistent. And not flushed is not > persistent. > > -- > You received this message because you are subscribed to the Google Groups > "Google App Engine for Java" group. > To post to this group, send email to google-appengine-j...@googlegroups.com. > To unsubscribe from this group, send email to > google-appengine-java+unsubscr...@googlegroups.com. > For more options, visit this group > athttp://groups.google.com/group/google-appengine-java?hl=en. -- You received this message because you are subscribed to the Google Groups "Google App Engine for Java" group. To post to this group, send email to google-appengine-j...@googlegroups.com. To unsubscribe from this group, send email to google-appengine-java+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/google-appengine-java?hl=en.
