Feeds for Late Arriving Data

When acquiring data for the data warehouse from source systems, it can be useful to make a clear distinction between the time at which an event occurred, and the time at which the event was recorded by the source system. In the simplest case, the source system records the event at the time it occurs and the anomalies described below do not happen. But in cases where there is a delay between the actual time of the event, and the time the record of the event is received by the source system, then there's a trap that needs to be avoided.