ref. StreamBase or article “One Size Fits All”: An Idea Whose Time Has Come and Gone

outbound query processing: where queries are run after the streaming data is indexed and stored.

inbound query processing:  data is inputed into a system and got processed as they “fly by” in memory by the
query network, the results are pushed to the client. Reads or writes to storage are optional and can be executed asynchronously in many cases.