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RE: Upgrading ozone applications

That sounds very interesting.

If I don't use serialVersionUID - then what versionnumber are you thinking
about ?

Do I need to have both versions of my object in scope ? E.g. can I read a
version1 object out of Ozone and the 'externalize' it to my updated version
2 object ?

Would you happen to know of a place where code like that can be studied in
more detail ?

-----Original Message-----
From: ozone-users-owner@ozone-db.org
[mailto:ozone-users-owner@ozone-db.org]On Behalf Of Gerd Mueller
Sent: Tuesday, May 29, 2001 1:03 PM
To: ozone-users@ozone-db.org
Subject: Re: Upgrading ozone applications

> I guess that I could live with having to do an effort to get the upgrade
> done.
> I was just wondering if somebody has solved this problem in some form ?
> Does Ozone work with serialization in the background ?

Yes, it does. And if you make your database objects 'Externalizable' and
implement read/writeExternal clever you can do a pretty good schema
evolution. You can use than a version number (not serialVersionUID !) ,
it in writeExternal, check it within readExternal and do additional actions
if the version number has a particular value. Thus you can avoid the normal
serialization schema evolution limitations, e.g. removing a member.

Best Regards,
Gerd Mueller                                   mailto:gerd@smb-tec.com
SMB GmbH                                        http://www.smb-tec.com