By default, the view is in a "smart mode": It is in Deferred mode if nobody is interested in its data, and it is synchronized and goes to Immediate mode if there is a client interested in receiving notifications of changes in that view's data.

In other words, a view in Default mode is effectively in Deferred mode if no listeners registered to be notified of its changes, and it is effectively in Immediate mode if there are such listeners (for example, if there is GUI control bound to it).

When a change in base data occur, the view is not synchronized with it immediately. It is allowed to go stale, out of sync with its base data as long as there are no requests for this view's data. The view is synchronized on demand, that is, it is synchronized when any request for its data arrives.

The view is synchronized with its base data automatically and immediately after any change in its base data occurs. The view is kept synchronized with its base data at all times.