Yeah from what I recall RETE can be quite memory intensive in that it keeps the results of any intermediate rule computations that result from changing inputs i

Yeah from what I recall RETE can be quite memory intensive in that it keeps the results of any intermediate rule computations that result from changing inputs in memory, in the hope that it will speed up answering subsequent queries (similar to how you might want to incrementally update a materialized view). Subsequent algorithms explored trading off memory consumption for query latency (amongst other differences).