A method is provided. The method includes receiving a plurality of data streams at a computing device, processing first event data of a first data stream of the plurality of data streams in accordance with a first key, and determining whether second event data of a second data stream of the plurality of data streams is stored in a cache memory in accordance with the first key. The second event data is to be joined with the first event data. The method further includes performing a join operation of the first event data and the second event data at least partially in view of whether the second event data is stored in the cache memory.