This is something that can be tackled by doing lazy condition evaluation (backward), which may be included in the future as an option.
In most cases, I don't think the impact on performance would really be anything much. Of course there are some cases where it would - one "hack" which has been suggested before - is to put a lazy check inside the consequence itself. So the "condition" is not a condition node, but just a check before the consequence does what it wants. This "hack" is then invisible to the engine, but may work in some special cases. On 1/17/06, Peter Van Weert <[EMAIL PROTECTED]> wrote: > > As far as I know you cannot really do this, because Drools is a > Rete-based system, which is an eager evaluation algorithm. This means > the complete conflict set gets cumputed, followed by the selection of > one to fire (match - select - act). I guess the XOR group will then > delete the other rules from the agenda as well. That's my guess of > course, since I don't know much about the internal details of Drools. > And yes, you are right, this could get really inefficient in some cases, > but, in general, this remains limited. If it really starts to become a > performance issue, you should consider using a system based on a lazy > evaluation algorithm... > > Yours, > Pé > > > Sinha, Amitesh wrote: > > If the XOR group is used, all conditions are evaluated and only one > > consequence is executed. E.g., > > If I have N rules, all N conditions are evaluated before one consequence > > is triggered. If the value of N is very high, this is going to degrade > > the performance drastically. > > > > <rule-set> > > > > <rule name=" Rule1"> > > - > > - > > - > > </rule> > > <rule name=" Rule2 "> > > - > > - > > - > > </rule> > > . > > . > > . > > > > <rule name=" RuleN "> > > - > > - > > - > > </rule> > > </rule-set> > > > > > > Is there a way we can use so that when one condition is satisfied, none > > of the other conditions are evaluated? > > > > > > Thanks in advance, > > > > Amitesh > > > > http://www.patni.com > > World-Wide Partnerships. World-Class Solutions. > > _____________________________________________________________________ > > > > This e-mail message may contain proprietary, confidential or legally > > privileged information for the sole use of the person or entity to > > whom this message was originally addressed. Any review, e-transmission > > dissemination or other use of or taking of any action in reliance upon > > this information by persons or entities other than the intended > > recipient is prohibited. If you have received this e-mail in error > > kindly delete this e-mail from your records. If it appears that this > > mail has been forwarded to you without proper authority, please notify > > us immediately at [EMAIL PROTECTED] and delete this mail. > > _____________________________________________________________________ > > > > >
