[rules-users] optimization on a lot of simple rules

[Greg Barton]

Now this finally rises to something that needs rules. :)  In all of the previous examples you've given you could just have a Map<ProductKey,Handler> where the Handler looks like this:

interface Handler {
  void handle(Product product, Decision decision);
}

...and the ProductKey consists of properties that uniquely identify how the Product is handled.  So, on it's own, that functionality did not require rules.

However, now that you've introduced more complex decisions, with varying data, to affect the Decision for each Property type, rules are more appropriate.

Is there any reason why you only have one of each object type in memory at one time?  Maybe if you state more of the problem requirements we can help you better.

--- On Mon, 7/20/09, nesta <nesta.fdb at 163.com> wrote:

> From: nesta <nesta.fdb at 163.com>
> Subject: Re: [rules-users] optimization on a lot of simple rules
> To: rules-users at lists.jboss.org
> Date: Monday, July 20, 2009, 4:14 AM
> 
> Thanks very much.
> But if for every rule, there is one algorithm or discount
> which means that
> result has nothing related with Product's id and usage. I
> can't merge all
> rules in one rule. At the same time, besides Product and
> Decision fact type,
> there are more fact types.
> For example:
> rule 1
>     when
>          Decision()
>          Subscriber(gender ==
> "male" or "female")
>          Service(name ==
> "ftp" or "http")
>          Product(id == 1)
>          ......
>    then
>          ......
> end
> rule 2
>     when
>          Decision()
>          Subscriber(gender ==
> "male" or "female")
>          Service(name ==
> "ftp" or "http")
>          Product(id == 2)
>          ......
>    then
>          ......
> end
> 
> .....
> .....
> 
> In this scenario, if there are 1000 rules,  there will
> be a lot of JoinNode.
> But in runtime, there is only one Decision instance, one
> Subscriber instance
> and Service instance.
> 
> If I define all data in one fact type, I think that there
> are not a lot of
> JoinNodes.
> 
> Is there any other method?
> 
> 
> 
> Wolfgang Laun-2 wrote:
> > 
> > Well, what is the realtion between id, usage and the
> result that's to be
> > stored in a Decision or a global?
> > 
> > Typically, such rules could be written as
> > 
> > rule x
> > no-loop true
> > when
> >     $d : Decision()
> >     $p :Product( id == 1, $usage :
> usage )
> > then
> >     compute/store value, depending
> on the formula for id == 1 (using
> > usage)
> > end
> > // similar rule for id == 2,3,...
> > 
> > If value is a straightforward function of id (and
> usage), then implement a
> > function compValue and use a single rule, e.g.:
> > 
> > rule x
> > no-loop true
> > when
> >     $d : Decision()
> >     Product( $id : id, $usage :
> usage)
> > then
> >    modify $d value to compValue( $id, $usage
> )
> > 
> > Distinguishing all individual combinations of id and
> usage on the LHS
> > seems
> > excessive.
> > 
> > The ordering of CEs also affects execution times.
> > 
> > -W
> > 
> > On 7/20/09, nesta <nesta.fdb at 163.com>
> wrote:
> >>
> >>
> >> In this scenario, there are 1000 products,
> different product has
> >> different
> >> price, besides this, the price is affected by
> usage. I want to use
> >> Product.id to match the rules.
> >>
> >> As you mentioned "The crude duplication of rules
> where only the constant
> >> to
> >> be matched with
> >> Product.id varies can, most likely, be avoided."
> >>
> >> How to avoid it in this scenario?
> >>
> >>
> >> Wolfgang Laun-2 wrote:
> >> >
> >> > It's difficult to suggest an optimized form
> for your rules 1-infinity,
> >> > since
> >> > we do not know what you want to achieve.
> >> >
> >> > The crude duplication of rules where only the
> constant to be matched
> >> with
> >> > Product.id varies can, most likely, be
> avoided.
> >> >
> >> > -W
> >> >
> >> >
> >> >
> >> > On Sun, Jul 19, 2009 at 3:15 PM, nesta <nesta.fdb at 163.com>
> wrote:
> >> >
> >> >>
> >> >> Hi,
> >> >>
> >> >> I am a newbie in drools. There are a lot
> of simple rules in a
> >> scenario.
> >> >> For example
> >> >> rule 1
> >> >>    when
> >> >>        Product( id
> ==1, usage == 1)
> >> >>        $decision :
> Decision()
> >> >>    then
> >> >>     
>    $decision.setValue(1);
> >> >> end
> >> >>
> >> >> rule 2
> >> >> when Product( id ==2, usage == 1)
> >> >>  $decision : Decision()
> >> >> rule 3
> >> >> when Product( id ==3, usage == 1)
> >> >>  $decision : Decision()
> >> >> rule 4
> >> >> when Product( id ==4, usage == 1)
> >> >>  $decision : Decision()
> >> >> rule 5
> >> >> when Product( id ==5, usage == 1)
> >> >>  $decision : Decision()
> >> >> ......
> >> >>
> >> >> I have a Product fact whose id = 5 and
> usage = 1, in my first
> >> thinking,
> >> >> only
> >> >> rule 5 is matched, there should be not
> much more different between 1
> >> rule
> >> >> and a lot of rules in runtime.
> >> >>
> >> >> But the result shows that they are
> different. More rules will cost
> >> more
> >> >> time. If there are 1 thousand rules, some
> Node and Sink will execute 1
> >> >> thousand times.
> >> >>
> >> >> My question is how to optimize this
> scenario?
> >> >> --
> >> >> View this message in context:
> >> >>
> >> http://www.nabble.com/optimization-on-a-lot-of-simple-rules-tp24556724p24556724.html
> >> >> Sent from the drools - user mailing list
> archive at Nabble.com.
> >> >>
> >> >>
> _______________________________________________
> >> >> rules-users mailing list
> >> >> rules-users at lists.jboss.org
> >> >> https://lists.jboss.org/mailman/listinfo/rules-users
> >> >>
> >> >
> >> >
> _______________________________________________
> >> > rules-users mailing list
> >> > rules-users at lists.jboss.org
> >> > https://lists.jboss.org/mailman/listinfo/rules-users
> >> >
> >> >
> >>
> >> --
> >> View this message in context:
> >> http://www.nabble.com/optimization-on-a-lot-of-simple-rules-tp24556724p24563725.html
> >> Sent from the drools - user mailing list archive
> at Nabble.com.
> >>
> >> _______________________________________________
> >> rules-users mailing list
> >> rules-users at lists.jboss.org
> >> https://lists.jboss.org/mailman/listinfo/rules-users
> >>
> > 
> > _______________________________________________
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> > rules-users at lists.jboss.org
> > https://lists.jboss.org/mailman/listinfo/rules-users
> > 
> > 
> 
> -- 
> View this message in context: http://www.nabble.com/optimization-on-a-lot-of-simple-rules-tp24556724p24566350.html
> Sent from the drools - user mailing list archive at
> Nabble.com.
> 
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