Hello All, I am implementing a Rules Engine with Drools that has a fact count in the millions. I have tried to remove some of the facts from the system to cut down on my load. To do this, a layer has been place "over" Drools that filters out facts before they enter the system. This approach helps a bit, but it has introduced a new problem. To determine which facts should make their way into the system, a large number a queries are run against working memory. I have placed a fact counter into my system and it suggests every query is inserted into the system as a fact. Due to the large number of queries, the fact counter reported over 400000 fact queries were placed into the system. This accounts for 40+% of the facts in the system. This leads me to a couple of questions. First, is the fact counter giving me accurate information? Do all of the queries get entered into working memory, and stay there? Secondly, if all these queries are entered into the system, and stay there, does it effect performance? If that's true, are the queries eventually removed, or do I have to do something explicit to remove them? If anyone has other recommendations for optimizing large fact counts please let me know. Thanks for your time, Dan -----Original Message----- From: rules-users-bounces(a)lists.jboss.org [mailto:rules-users-bounces@lists.jboss.org] On Behalf Of Marcus Ilgner Sent: Thursday, July 03, 2008 9:24 AM To: Rules Users List Subject: Re: [rules-users] insert a collection/ArrayList of facts On Thu, Jul 3, 2008 at 2:55 PM, thomas kukofka <thomaskukofka(a)web.de&gt; wrote: rule? Hi Thomas, I'm not sure if this is what you want but I think this should work: rule "ItemsFromList" when $list : List(); $item : MyObject() from $list; then // do something end Best regards Marcus _______________________________________________ rules-users mailing list rules-users(a)lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-users