session (question retyped)

ok maybe my question is not really clear...
the thing is that i am programming in asp.net but my boss doesn't was me to utilise DataViewState in any control due to problems of perfermance. it happens that when I use dataset to store data, each time that I have a poskback everething is lost and the only way to get the dataset back is using a session, again my boss is concerned by a great number of user using big in-memory session... so I need a method to get rid to the session which are not going to be used in order to release memory resources.
Thanks!

So you can't use ViewState, and you can't use Session, yet you still want to maintain state? Are you editing or paging in your datagrid? You're almost certainly going to have to use ViewState as far as I can see. Sorry.