Re: [rules-users] Performance issues with a rule that includes LHS functions

Wolfgang, Unfortunately, it would be very difficult to introduce a procedural/algorithmic "branch" into the program flow.

an accumulate function to extract the desired array element and then process the rest of the rule's login?

Mike Goldner m: 617.909.3009 From: Wolfgang Laun <wolfgang.laun(a)gmail.com&gt; Reply-To: Rules Users List <rules-users(a)lists.jboss.org&gt; Date: Friday, May 4, 2012 1:05 PM To: Rules Users List <rules-users(a)lists.jboss.org&gt; Subject: Re: [rules-users] Performance issues with a rule that includes LHS functions Looks like an anti-pattern to me: you can expect O(n^3) effort for inserting Data facts. This is something where a procedural/algorithmic solution is preferable to a rule based solution. -W On 4 May 2012 18:44, Mike Goldner <mike(a)thegoldners.com&gt; wrote: > I have a rule that is suffering severe performance degradation as I insert > facts into the (stateful) session. In my simplified example, the first > 100 fact insertions take less than 10ms per fact. By the 1000th fact, > insertions are taking about 850ms per fact. In production, the impact is > much more severe, reaching 5000ms or more by the 1000th insertion. The > number of facts per execution can vary from a few hundred to a few > thousand. > > I've created a simplified example that demonstrates the problem: Imagine > that there is a line plotted through a 3-dimensional plane and it is > necessary to ensure that each plotted coordinate is an equal distance from > the adjacent coordinates. I realize that the math isn't correct, but it > is sufficient for the example. > > The constraint (and source of performance degradation) imposed by my data > source is that the plane (X, Y, or Z) is variable and it is defined by an > separate index that serves as a pointer into the coordinate list. If I > remove the function calls, the problem disappears. > > Any suggestions on how I could rewrite the rule? > > Here is my rule: > > package test; > > declare Data > plane : int > coordinates : java.util.List > end > > rule "Performance degradation with functions." > dialect "mvel" > when > $current : Data( $currentPosition : getPosByAxis(plane, > coordinates) ) > $before : Data( $beforePosition : getPosByAxis(plane, > coordinates) < > $currentPosition) > not Data( getPosByAxis(plane, coordinates) > > $beforePosition && < > $currentPosition) > $after : Data($afterPosition : getPosByAxis(plane, > coordinates) > > $currentPosition) > not Data(getPosByAxis(plane, coordinates) < $afterPosition > && > > $currentPosition) > eval ( ($currentPosition - $beforePosition) == > ($afterPosition - > $currentPosition) ) > then > System.out.println("Rule RHS fired."); > end > > function Double getPosByAxis(int plane, java.util.List coordinates) { > > return (Double) coordinates.get(plane); > > } > > Thanks, > > Mike Goldner > > > _______________________________________________ > 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 _______________________________________________ rules-users mailing list rules-users(a)lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-users