> > Betreff: semantics of deleted objects > Datum: Wed, 2 Sep 2015 10:43:21 +0200 > Von: Tilmann <tilmann_...@gmx.de> <mailto:tilmann_...@gmx.de> > Antwort an: jdo-user@db.apache.org <mailto:jdo-user@db.apache.org> > An: jdo-user@db.apache.org <mailto:jdo-user@db.apache.org> > > > Hi, > I posted this question a while ago on StackOverflow: > https://stackoverflow.com/questions/27585579/jdo-semantics-of-deleted-objects > <https://stackoverflow.com/questions/27585579/jdo-semantics-of-deleted-objects> > It didn't get answered yet. > > Here is the question: > > =========== > > I've been studying the JDO 3.0 spec and I'm not sure what the semantics > of |delete()| and |refresh()| are supposed to be. > > Suppose I have two optimistic sessions, pm1 and pm2, both access the > same object. Pm1 deletes the object and commits. Then what happens in > pm2 if: > > 1. > > pm2 deletes the object and tries to commit, should that work? It's > wouldn't be a real conflict if both delete it. Actually, it would be a conflict. If your application thought it was deleting an object but the object wasn’t there, that would be an error. The delete would fail and the transaction would fail. > > 2. > > pm2 modifies the object (make dirty) and calls refresh(). Should I > get an ObjectNotFound exception? Refresh would call the database and try to load the object again and would fail. > 3. > > pm2 deletes the object and calls |refresh()|. According to the spec, > |refresh()| should not change the object's state. That is how I read the spec as well. > But should it > still fail with |ObjectNotFound|? If refresh should fail, how can I > ever recover from such a situation, because I can't undelete the > object? Maybe when you file your JIRA, you can describe what you would like to do to recover this situation, in as much detail as possible. > > ============ > > Could someone point me to some relevant documentation? The specification sections on life cycle and refresh have some information but perhaps not the definitive answers you are looking for. > > Should I maybe write an JIRA bug report to enhance the spec? That would be a good idea.
Craig > > Cheers, > Tilmann > > > > > > > Craig L RussellArchitect, Oraclehttp://db.apache.org/jdo408 276-5638 > mailto:craig.russ...@oracle.comp.S. A good JDO? O, Gasp! >
