Locking datafile problem using oracle agent

Question

Hi All
we are facing locking datafile problems when we are taking backups using oracle agent
in veritas we have selected the option not to lock files when taking backups
is there any other settng which we have missed so that it doe s not lock files
regards
kedar

Answer 1

If you use a version locking policy, you should use a version field, not reuse your primary key for that. If you map the version field (you don't have to), you need to map it as read only. This makes sense: you don't want the application to change this version field, only TopLink should change it. This is where your exception comes from.
If you want to use existing database fields for optimistic locking, you should use a field locking policy. It does not make sense to use the primary key for that: it never changes, so you never know when the object has been changed by another user.
So you can do two things now to fix your code:
create a version column in your database and use a version policy (preferably numeric) or use a field locking policy and use job and salary, or all fields)
There is a pretty good description of locking policies in the TopLink guide:
http://www.oracle.com/technology/products/ias/toplink/doc/10131/main/_html/descun008.htm#CIHCFEIB
Hope this helps,
Lonneke