Processing of streaming data with keyed aggregation

[0019]In accordance with an aspect of the present invention, a capability is provided for improving processing of streaming data by employing a keyed aggregation operator that uses replacement of older information with more recent information. A capability is provided for aggregating the values from a stream of data events, in which, for example, there is a flow of events (i.e., records) where some events are for the same entity as previous events and they replace the older events (i.e., records related to an entity received earlier), and these replaced events no longer factor in the aggregation calculations.

[0020]As one example, in order to incrementally calculate aggregations even in light of events for specific entities being replaced by newer events for those entities, the most recent event for each unique replacement key value(s) is maintained, running aggregations are kept, and the aggregations are output. When a new event arrives, in one example, if a previous event exists for t