Hi karthi,

Rollback segment is an object which every transactions can share access. So no users can be particularly pinned with a particular rollback segment. Simultaneous transaction can write into same rollback segment, even to same extent but not to same block. And transactions can't span accross rollback segments.

So you create one public rollback segment. And whenever a session is started, Issue the first command to set the transaction to a specific rollback segment.

And your's is i think an OLTP type of application, so create few rollback segments with lesser size.

HTH.