According to Section 3.3.7 "StatelessKnowledgeSession" of http://downloads.jboss.com/drools/docs/5.1.1.34858.FINAL/drools-expert/ht... the Drools document , "the act of calling execute() is a single-shot method that will internally instantiate a StatefulKnowledgeSession". Why StatelessKnowledgeSession instantiates a new statefulKnowledgeSession object on Each execute()? Instead, can it be implemented as inserting the fact into an existing empty statefulKnowledgeSession, and retract the fact after statefulKnowledgeSession.fireAllRules()? I think the current implementation will cause StatelessKnowledgeSession to be slower than statefulKnowledgeSession, as opposed to "common sense" that the former is less complex and should be faster. Any performance benchmark on Stateless v.s. Stateful Sessions? -- View this message in context: http://drools-java-rules-engine.46999.n3.nabble.com/Why-StatelessKnowledg... Sent from the Drools - User mailing list archive at Nabble.com. _______________________________________________ rules-users mailing list rules-users(a)lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-users

I see. Thank you. For instance, retracting a fact with lots of pending activations associated with this fact could me expensive. Am I right? 2011/1/27 Esteban Aliverti <esteban.aliverti(a)gmail.com&gt; > Sessions are cheap to create. > The problem of removing all the facts and then insert new ones is that > depending on you rules, could be much more expensive than throw the old > session and create a new one. And you should also think about globals as > well. Removing a Fact is not just taking it off from a list. There is a lot > of logic involved there. > Is like if you have a populated List and you want to remove all its items > and fill it with new ones (from another List for example). > What would you use? > > originalList.clear(); > originalList.addAll(anotherList); > > or > > originalList = new ArrayList(anotherList); > > Best Regards, > > XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX > > Esteban Aliverti > - Developer @ http://www.plugtree.com > - Blog @ http://ilesteban.wordpress.com > > > > On Thu, Jan 27, 2011 at 5:45 AM, hyjshanghai <hyjshanghai(a)gmail.com&gt;wrote: > >> >> According to Section 3.3.7 "StatelessKnowledgeSession" of >> >> http://downloads.jboss.com/drools/docs/5.1.1.34858.FINAL/drools-expert/ht... >> the Drools document , "the act of calling execute() is a single-shot >> method >> that will internally instantiate a StatefulKnowledgeSession". >> >> Why StatelessKnowledgeSession instantiates a new statefulKnowledgeSession >> object on Each execute()? >> >> Instead, can it be implemented as inserting the fact into an existing >> empty >> statefulKnowledgeSession, and retract the fact after >> statefulKnowledgeSession.fireAllRules()? >> >> I think the current implementation will cause StatelessKnowledgeSession >> to >> be slower than statefulKnowledgeSession, as opposed to "common sense" >> that >> the former is less complex and should be faster. Any performance >> benchmark >> on Stateless v.s. Stateful Sessions? >> -- >> View this message in context: >> http://drools-java-rules-engine.46999.n3.nabble.com/Why-StatelessKnowledg... >> Sent from the Drools - User mailing list archive at Nabble.com. >> _______________________________________________ >> rules-users mailing list >> rules-users(a)lists.jboss.org >> https://lists.jboss.org/mailman/listinfo/rules-users >> > > > _______________________________________________ > rules-users mailing list > rules-users(a)lists.jboss.org > https://lists.jboss.org/mailman/listinfo/rules-users > > -- Best Wishes, Huang, Yijian _______________________________________________ rules-users mailing list rules-users(a)lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-users