Re: [rules-users] Will the alternative lead to a better performance?

Hi Edson, Thanks for your reply. WRT your reply below (highlighted): In our environment, we only have one class and several instances of that class. We currently do not use the "==" constraint and we do a equals() on the name string. However, I am going to use "==" since there will be only one object with a particular name. Also, can you define what the number for "huge" is? How many buckets get defined initially for the hashing. Can I modify the initial size of this collection so that I will not have clashes. ( I happen to know exactly how many objects will be thrown into the engine) Is this set through configuration or would I have to recompile code to do this? Thanks, Prem On 3/23/07, Edson Tirelli < tirelli(a)post.com&gt; wrote: > > > Stephen, > > As long as you use an "==" constraint as your example shows, the > first alternative will be more performatic. This is because drools > indexes facts based on your constraints. So, your first case will > require a single "==" comparison to find user name "A" and a single > comparison to find user name "B". Of course, if you have huge amound of > objects where hashcode for name start to clash, you may have more than > one comparison, but the effect is negligible when compared to all other > costs of having that many facts. > > Second alternative works and will also hash object types, but it will > create a lot more infrastructure classes and Rete Nodes to deal with > your 500 different classes. So it is a worst alternative for the > proposed scenario. > > []s > Edson > > > Premkumar Stephen wrote: > > > Hi, > > > > Consider that I have 500 instances of interface userI. Now, there are > > 3000 rules currently written based on a combination of these > instances. > > > > if { > > $a : userI (name = "A") > > $b : userI (name = "B") > > } > > then > > { > > //do some actions > > } > > > > How many tests are needed for a match in the RETE network for this > rule? > > > > If I created 500 classes, one for each object, such as UserA > > implements userI and so on... my rule will look like: > > > > if { > > $a : UserA() > > $b : UserB() > > } > > then > > { > > //do some actions > > } > > > > Will this lead to better performance since there will only be one such > > instance of this object? > > > > As for class-loading concerns, will there be a parsing/memory penalty > > to be paid for having 500 classes now instead of one? > > > > Thanks! > > > > >------------------------------------------------------------------------ > > > >_______________________________________________ > >rules-users mailing list > &gt;rules-users(a)lists.jboss.org > >https://lists.jboss.org/mailman/listinfo/rules-users > > > > > > > -- > Edson Tirelli > Software Engineer - JBoss Rules Core Developer > Office: +55 11 3124-6000 > Mobile: +55 11 9218-4151 > JBoss, a division of Red Hat @ www.jboss.com > > > _______________________________________________ > rules-users mailing list > rules-users(a)lists.jboss.org > https://lists.jboss.org/mailman/listinfo/rules-users > -- Regards, Prem _______________________________________________ rules-users mailing list rules-users(a)lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-users