persistent data locks

I need to replicate row data from Oracel 7.1.3 into an external database, modify that data, and then update the changes back to Oracle. This is in support of a mobile computing application.

The problem is I must disconnect from Oracle after replication and then reconnect later for update.
Oracle data locking methods that I'm aware of will not maintain data locks once a session is terminated.

Does Oracle provide a method for maintaining some kind of persistant data lock that isn't terminated when the Oracle connection is terminated?

Any other ideas on solving this problem?

Are there any development tools available that solve this and other problems related to mobile computing (like data synchronization)?

Thanks for any help!

-- 
Tom Nelson
IGS, Inc., Boulder, CO
tom_at_igs.com