I've been trying to optimize our stateful rules to run a bit faster, currently they can't quite keep up with the events coming into the session. A lot of our rules have to find the fact whose attribute is the smallest/largest value of all the facts of that type in working memory. I had originally written the rules to do a min accumulate to find the min value of the attribute, then a regular pattern to find the actual fact with that min value. Some of the fact types actually have two fields that must be used to find the min - think of them as a category and a score. For those I did two accumulate mins, one to find the lowest category, one to find the lowest score in that category, and then a third rule to find the fact with that min category and min score. I recently refactored all the rules to use the paradigm of one rule that matches the fact type I'm interested in, and a second rule that uses the not operator to express that there be no facts whose attribute is a higher value than the fact I just matched. In the contrived test I wrote, this seemed to perform better, but it's hard to tell if they are performing better or not with production data flowing through them. I know of a third option - writing my own accumulate functions - which I will probably try next. This should allow me to find the min/max fact with just one iteration over the facts, vs multiple iterations like my first approach. I don't know how it will compare to using the exists method though. Any feedback on these three different approaches? Any other ideas on the best way to do this? -- View this message in context: http://drools.46999.n3.nabble.com/Best-performing-way-to-process-facts-in... Sent from the Drools: User forum mailing list archive at Nabble.com. _______________________________________________ rules-users mailing list rules-users(a)lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-users

Yes, I definitely do have to account for the min/max changing due to facts updating. How does drools handle the exists constraint internally? Is it able to take advantage of caching and the rete network or does it have to look through all the facts each time that rule is being evaluated? If that's the case, writing my own min/max accumulate might be more efficient that the approach of using an exists constraint to find the min/max fact. -- View this message in context: http://drools.46999.n3.nabble.com/Best-performing-way-to-process-facts-in... Sent from the Drools: User forum mailing list archive at Nabble.com. _______________________________________________ rules-users mailing list rules-users(a)lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-users