Question regarding Basic Notification

Hi, Can i clarify if this is the behaviour of Basic Notification.

For Integration components with Basic Notication, the Integration Component will keep performing an SQL SELECT on the buffer table as long as there are records in it. When the buffer table is empty, the Basic Notification will poll the table at intervals according to value specified in the Polling Interval in the adapter configuration.

Is the above understanding correct? By the way, if i do not perform a delete how does the Basic Notification knows that it has already selected that record previously?