Date Added: Oct 2009
The cycle of processing the data in many application domains is complex and may involve real-world activities that are external to the database, e.g., wet-lab experiments, instrument readings, and manual measurements. These real-world activities may take long time to prepare for and to perform, and hence introduce inherently long time delays between the updates in the database. The presence of these long delays between the updates, along with the need for the intermediate results to be instantly available, makes supporting real-world activities in the database engine a challenging task. This paper addresses these challenges through a system that enables users to reflect their updates immediately into the database while keeping track of the dependent and potentially invalid data items until they are re-validated.