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Re: To Falko, questions about type lookup, instance "ownership"
On Sat, 21 Aug 1999, you wrote:
> Does Ozone yet have the ability to lookup and return a tree of all its
> stored objects? What about all objects of a type? What about all
> objects of a type and its subtypes? (As in, everything inheriting from
> Object!)
Very good point, since we are just discussing ODMG compliance. Yes, it is
possible to implement methods to browse the type tree of the database. In fact,
we have started that with the objectsOfClass() method. However, if we decide to
implement such methods, the door to a garbage collector is closed. Because then
you can access objects no matter if the are named or referenced.
Anyway, if we really want it, we need a good interface for the type tree
methods. Any ideas?
>
> This might make a generic tree-structured DB maniulator /report writer
> do-able. I admit however, this introduces security issues: Should
> another application be able to even "see" objects created by another app
> (or user)? Much less delete them?
So far, this is no problem. The only way to access the state of an object is to
call methods on it. So, if an application calls a method for a proxy that it
has received via the type methods but does not have the right permissions, it
will simply get an "permission denied" exception.
>
> Also, is there any thought to the concept of object instance
> "ownership". This is the "uses", vs. "owns' issue.
Not yet. IMHO this is a problem of the application, not of the underlaying
DBMS. Wrong? How can we support owned objects on DB level?
Falko
--
______________________________________________________________________
Falko Braeutigam mailto:falko@softwarebuero.de
softwarebuero m&b (SMB) http://www.softwarebuero.de