Hallo,
as discussed here [1] and there [2].
I am seeking for a solution where the following works:
Room r = new Room();
getContext().registerNewObject(r);
Meeting m = new Meeting();
r.addMeeting(m); //[3]
I get heavy memory problems in my calculations, while doing the
following procedure 100,000 times: I create a meeting, calculate sth.
and remove it. Cayenne forces me to register all the 'meetings' and will
reference them although I don't need them anylonger. But I don't know
when I won't need them.
So one solution comes from Mike Kienenberger as discussed before and
another solution could be to create sth. like a readonly context, where
I could copy the results in a normal DataContext if I am done. So can I
simply put the objects into the ObjectStore by a WeakReference or should
I know more about the internals. (I think I should!)
May be a readonly context could even improve performance, because of the
nonexistent 'registering' overhead.
Now my questions are:
1. Is there already a (similar) solution for the ReadOnlyContext?
2. Will cayenne implement Mike Kienenberger's solution? Or others? Can I
open a JIRA issue/feature request [3]?
3. Are there other ORM's that solve this. (Not worth to exchange, but
worth to know :-)
4. Could JPA help me here or will cayenne silently 'add the meetings' as
in normal cayenne setup?
Bye,
Peter.
[1]
http://objectstyle.org/cayenne/lists/cayenne-user/2007/03/0181.html
[2]
http://objectstyle.org/cayenne/lists/cayenne-user/2007/04/0054.html
[3]
Where the user can decide if a context does then
"throw an explicit exception", "add m silently and make it persistent"
or "add m silently, but don't make persistent", if an unregistered
object like 'm' will be added to a registered one like 'p' (or the other
way around)
And without registering one object (2 unregistered) cayenne shouldn't
throw NPE's.
