[rules-users] Convert logic to DRL rules
Edson Tirelli
tirelli at post.com
Mon Feb 19 16:45:51 EST 2007
Vlad,
What we can say for sure as a general rule is that flat object
structures make rules "writing" easier. So, it is easier to specify,
implement and maintain rules in cases where you work with flat domain
models.
When talking about performance, we can say that it is impacted by the
design of your object model, but it is not totallu dependent of the
nesting level of your business object. Usually you also get better
performance with flat object models, because with "simple" rules, it is
easier for the engine to optimize it. But that is not a general rule, as
you can have good performance with highly nested domain models if you
take some care when writing your rules.
So, if you are worried about performance, some tips that help:
* avoid EVALs at all cost. The engine can do almost nothing to optimize
them.
* write your most constraining facts first in the rule, and your most
constraining constraints first in the pattern
* try to always use regular constraints. Return value constraints and
predicate constraints are not optimized in current implementation.
Following the above tips will make you infer several other tips and
understand why it is usually more difficult to work with highly nested
domain models.
[]s
Edson
Olenin, Vladimir (MOH) wrote:
>To improve my understanding of DROOLS a bit, just a small follow up
>question.
>
>If the modification of the business domain model is correct and will result
>in the correct behavior, I wonder what kind of performance implications such
>modification will bring (to compare with 'flatten' model)? Would the
>performance become worse, better or remain approximately the same (for a
>significant number of rules & fact objects)? Currently I'm at the cross
>roads whether to create such artificial 'inverted index' for my application
>or not (I didn't know that the connective constraints are available in
>3.1M...).
>
>Thanks,
>
>Vlad
>
>-----Original Message-----
>From: rules-users-bounces at lists.jboss.org
>[mailto:rules-users-bounces at lists.jboss.org] On Behalf Of Edson Tirelli
>Sent: 19 February 2007 11:05
>To: Rules Users List
>Subject: Re: [rules-users] Convert logic to DRL rules
>
>
> Vlad,
>
> I think that for Bill's case, the object structure is flatten already
>(what is good for rules). Creating nested objects will actually make it
>more difficult to write the rules...
>
> Just my 0.02c
>
> []s
> Edson
>
>Olenin, Vladimir (MOH) wrote:
>
>
>
>>I guess if you modify the business objects a bit (in quite weird way - I
>>think it would be rather a shortcut than a solution) you can implement this
>>kind of logic: you need to swap property (zipcode, age, etc) and 'property
>>ownner' (Person) objects, so that you'll have:
>>
>>Person (id)
>>ZipCode (id, code)
>>Age (id, age)
>>Etc
>>
>>In this case you should be able to write:
>>
>>Rule X
>>When
>> $p: Person($id: id)
>> (
>> ZipCode(id == $id, code == "23456")
>> or ZipCode(id == $id, code == "68590")
>> )
>> And
>> (
>> Age(id == $id, age < 25)
>> Or Age(id == $id, age > 34)
>> )
>>Then
>> // do smth using $p
>>End
>>
>>
>>Or smth along those lines... Would that work?.....
>>
>>
>>Vlad
>>
>>
>>-----Original Message-----
>>From: rules-users-bounces at lists.jboss.org
>>[mailto:rules-users-bounces at lists.jboss.org] On Behalf Of Bill Zhang
>>Sent: 19 February 2007 09:14
>>To: Rules Users List
>>Subject: Re: [rules-users] Convert logic to DRL rules
>>
>>Hi Alex,
>>
>>Thank you for confirming this. Writing such a builder may take us a
>>lot of time because our business user is used to free style
>>Pascal-like authoring using quite complex logic. For example,
>>
>>IF
>>(
>>(
>> (Person.Age > 35 OR Person.Age < 25) AND
>> (Person.ZipCode =23546 or Person.ZipCode = 68590)
>>)
>>and
>>(
>> (Person.LastOrderPrice > 300 OR
>> (Person.TotalOrderNumber > 2)
>>)
>>)
>>OR
>>(
>>(
>> (Person.LastOrderCategory in ("098", "109") ) AND
>> (Person.ZipCode =74567 or Person.ZipCode = 23765)
>>)
>>and
>>(
>> (Person.LastOrderPrice > 1000 OR
>> (Person.TotalOrderNumber > 1)
>>)
>>)
>>...
>>
>>THEN Person.Status = "KT";
>>
>>Before I set out to write the builder, I would like to know whether
>>the new syntax can handle the above logic? Also, where can I find
>>document for the new syntax?
>>
>>I am also trying to find some existing open source Java library to
>>"flatten out" these complex logic - to break these complex logic to
>>atomic ones that can be handled by Drools. Do you have any
>>recommendation?
>>
>>Thanks a lot for your help.
>>
>>Bill Y.
>>
>>
>>
>>
>>On 2/19/07, Alexander Varakin <avarakin at optonline.net> wrote:
>>
>>
>>
>>
>>>We built a Rule Builder which creates drl with all possible
>>>combinations. In any case, drl syntax is not exactly business user
>>>friendly, so having such builder is not a bad idea.
>>>Simple Rule Builder can be implemented as an Excel spreadsheet, which
>>>can be easily parsed using POI library and then drl file produced.
>>>
>>>Steven Williams wrote:
>>>
>>>
>>>
>>>
>>>>Hi Bill,
>>>>
>>>>To implement your rules in 3.0.5 you would need to implement a rule
>>>>for each combination of age and zipCode.
>>>>
>>>>$a : Person(age > 35 zipCode == 23546)
>>>>then
>>>>$a.setStatus("KT");
>>>>
>>>>$a : Person(age < 25, zipCode == 23546 )
>>>>then
>>>>$a.setStatus("KT");
>>>>
>>>>$a : Person(age > 35, zipCode == 68590)
>>>>then
>>>>$a.setStatus("KT");
>>>>
>>>>etc..
>>>>
>>>>Steve
>>>>
>>>>On 2/19/07, *Bill Zhang* <billzhang2006 at gmail.com
>>>><mailto:billzhang2006 at gmail.com>> wrote:
>>>>
>>>> So Alex, if I only want to use the old syntax that is in production,
>>>> there is no way to implement my seemingly simple logic conditioning?
>>>>
>>>> Thanks for your help.
>>>>
>>>> On 2/18/07, Alexander Varakin < avarakin at optonline.net
>>>> <mailto:avarakin at optonline.net>> wrote:
>>>> > As far as I know this syntax is new and is available in SVN
>>>> only, you
>>>> > will have to wait till 3.1 is released or take source from SVN
>>>> and build it.
>>>> >
>>>> > Bill Zhang wrote:
>>>> > > Hi Steven,
>>>> > >
>>>> > > Thank you very much for your help. Really appreciate.
>>>> > >
>>>> > > I still got the same error, Unexpected token '|'. I did not
>>>> see "|" in
>>>> > > the document, only saw "||", which is supposed to be used with
>>>> > > columns.
>>>> > >
>>>> > > Ye
>>>> > >
>>>> > > On 2/18/07, Steven Williams < stevenw at objectconsulting.com.au
>>>> <mailto:stevenw at objectconsulting.com.au>> wrote:
>>>> > >> Hi Bill,
>>>> > >>
>>>> > >> I think it should be:
>>>> > >>
>>>> > >> $a : Person(age > 35 | < 25, zipCode == 23546 | == 68590)
>>>> > >>
>>>> > >> Edson, Mark or Michael can probably confirm or correct the
>>>> above syntax.
>>>> > >>
>>>> > >> Make sure you are running of the latest trunk.
>>>> > >>
>>>> > >> cheers
>>>> > >> Steve
>>>> > >>
>>>> > >>
>>>> > >> On 2/18/07, Bill Zhang <billzhang2006 at gmail.com
>>>> <mailto:billzhang2006 at gmail.com>> wrote:
>>>> > >> >
>>>> > >> > I tried:
>>>> > >> >
>>>> > >> > $a : Person(age > 35 || age < 25, zipCode == 23546 || ==
>>>>
>>>>
>>>>
>>>>
>>68590)
>>
>>
>>
>>
>>>> > >> >
>>>> > >> > Errors:
>>>> > >> > org.drools.rule.InvalidRulePackage : unknown:39:30
>>>> > >> Unexpected token '||'
>>>> > >> > unknown:39:40 mismatched token:
>>>> > >> [@246,1040:1041='<=',<47>,39:40];
>>>> > >> > expecting type '('
>>>> > >> > unknown:39:92 mismatched token:
>>>> > >> [@258,1092:1092='<',<46>,39:92];
>>>> > >> > expecting type '('
>>>> > >> >
>>>> > >> > I also tried
>>>> > >> >
>>>> > >> > $a : Person(age > 35 | age < 25, zipCode == 23546 | == 68590)
>>>> > >> >
>>>> > >> > Pretty much the same error.
>>>> > >> >
>>>> > >> > Based on the document, "||" is only valid for columns...
>>>> > >> >
>>>> > >> >
>>>> > >> > On 2/17/07, Bill Zhang <billzhang2006 at gmail.com
>>>> <mailto:billzhang2006 at gmail.com>> wrote:
>>>> > >> > > Thank you Steve. But I got syntax error using the
>>>>
>>>>
>>>>
>>>>
>>following.
>>
>>
>>
>>
>>>> > >> > >
>>>> > >> > > On 2/17/07, Steven Williams
>>>> <stevenw at objectconsulting.com.au
>>>> <mailto:stevenw at objectconsulting.com.au>> wrote:
>>>> > >> > > > In trunk I think you can use connective constraints:
>>>> > >> > > >
>>>> > >> > > > $a : Person(age > 35 | < 25, zipCode == 23546 | == 68590)
>>>> > >> > > > then
>>>> > >> > > > $a.setStatus("KT");
>>>> > >> > > >
>>>> > >> > > >
>>>> > >> > > >
>>>> > >> > > >
>>>> > >> > > > On 2/18/07, Bill Zhang < billzhang2006 at gmail.com
>>>> <mailto:billzhang2006 at gmail.com>> wrote:
>>>> > >> > > > >
>>>> > >> > > > > Hello,
>>>> > >> > > > >
>>>> > >> > > > > I am a new Drools user trying to convert the
>>>> following simple
>>>> > >> logic
>>>> > >> into
>>>> > >> > > > DRL:
>>>> > >> > > > >
>>>> > >> > > > > IF (Person.Age > 35 OR Person.Age < 25) AND
>>>> (Person.ZipCode =
>>>> > >> 23546
>>>> > >> or
>>>> > >> > > > > Person.ZipCode = 68590)
>>>> > >> > > > > THEN
>>>> > >> > > > > Person.Status = "KT";
>>>> > >> > > > >
>>>> > >> > > > > I found that it is not easy to convert the above
>>>> logic into
>>>> > >> ONE DRL
>>>> > >> rule.
>>>> > >> > > > >
>>>> > >> > > > > I tried something like this
>>>> > >> > > > >
>>>> > >> > > > > when
>>>> > >> > > > > $a: Person(age>35) or Person (age<25)
>>>> > >> > > > > $b: Person(Zipcode==23456) or Person (ZipCode == 68590)
>>>> > >> > > > > $c: $a and $b
>>>> > >> > > > > Then
>>>> > >> > > > > $c.setStatus("KT")
>>>> > >> > > > >
>>>> > >> > > > > But looks like I can not use
>>>> > >> > > > > $c: $a and $b
>>>> > >> > > > > becaue in Drools, you can only bind variable to
>>>> column, not
>>>> > >> to other
>>>> > >> > > > varaibles.
>>>> > >> > > > >
>>>> > >> > > > > Please advise how to do this. I would imagine this
>>>> should be
>>>> > >> quite
>>>> > >> > > > > simple, maybe I missed something quite obvious.
>>>> > >> > > > >
>>>> > >> > > > > I know that I can write custom Java method to do
>>>> this, but if
>>>> > >> I do
>>>> > >> > > > > that, I suppose I lose the power of RETEOO pattern
>>>> matching
>>>> > >> (pattern
>>>> > >> > > > resuing,
>>>> > >> > > > > etc.). So I prefer not to do that.
>>>> > >> > > > >
>>>> > >> > > > > I also understand I can break the above logic into 4
>>>> rules
>>>> > >> and that
>>>> > >> > > > > would be quite easy, but our business user is not used
>>>>
>>>>
>>>>
>>>>
>>to
>>
>>
>>
>>
>>>> > >> think in
>>>> > >> > > > > that way. Also, we have more complex logic than the
>>>> above. So
>>>> > >> what I
>>>> > >> > > > > want is to see if there is a way to convert this
>>>> > >> > > > > kind of logic in ONE DRL rule.
>>>> > >> > > > >
>>>> > >> > > > > Thanks in advance.
>>>> > >> > > > >
>>>> > >> > > > > Bill
>>>> > >> > > > > _______________________________________________
>>>> > >> > > > > rules-users mailing list
>>>> > >> > > > > rules-users at lists.jboss.org
>>>> <mailto:rules-users at lists.jboss.org>
>>>> > >> > > > >
>>>> > >> https://lists.jboss.org/mailman/listinfo/rules-users
>>>> > >> > > > >
>>>> > >> > > >
>>>> > >> > > >
>>>> > >> > > >
>>>> > >> > > > --
>>>> > >> > > > Steven Williams
>>>> > >> > > >
>>>> > >> > > > Supervising Consultant
>>>> > >> > > >
>>>> > >> > > > Object Consulting
>>>> > >> > > > Office: 8615 4500 Mob: 0439 898 668 Fax: 8615 4501
>>>> > >> > > > stevenw at objectconsulting.com.au
>>>> <mailto:stevenw at objectconsulting.com.au>
>>>> > >> > > > www.objectconsulting.com.au
>>>> <http://www.objectconsulting.com.au>
>>>> > >> > > >
>>>> > >> > > > consulting | development | training | support
>>>> > >> > > > our experience makes the difference
>>>> > >> > > > _______________________________________________
>>>> > >> > > > rules-users mailing list
>>>> > >> > > > rules-users at lists.jboss.org
>>>> <mailto:rules-users at lists.jboss.org>
>>>> > >> > > > https://lists.jboss.org/mailman/listinfo/rules-users
>>>> > >> > > >
>>>> > >> > > >
>>>> > >> > >
>>>> > >> > _______________________________________________
>>>> > >> > rules-users mailing list
>>>> > >> > rules-users at lists.jboss.org
>>>> <mailto:rules-users at lists.jboss.org>
>>>> > >> > https://lists.jboss.org/mailman/listinfo/rules-users
>>>> > >> >
>>>> > >>
>>>> > >>
>>>> > >>
>>>> > >> --
>>>> > >> Steven Williams
>>>> > >>
>>>> > >> Supervising Consultant
>>>> > >>
>>>> > >> Object Consulting
>>>> > >> Office: 8615 4500 Mob: 0439 898 668 Fax: 8615 4501
>>>> > >> stevenw at objectconsulting.com.au
>>>> <mailto:stevenw at objectconsulting.com.au>
>>>> > >> www.objectconsulting.com.au
>>>>
>>>>
>>>>
>>>>
>><http://www.objectconsulting.com.au>
>>
>>
>>
>>
>>>> > >>
>>>> > >> consulting | development | training | support
>>>> > >> our experience makes the difference
>>>> > >> _______________________________________________
>>>> > >> rules-users mailing list
>>>> > >> rules-users at lists.jboss.org
>>>>
>>>>
>>>>
>>>>
>><mailto:rules-users at lists.jboss.org>
>>
>>
>>
>>
>>>> > >> https://lists.jboss.org/mailman/listinfo/rules-users
>>>> > >>
>>>> > >>
>>>> > > _______________________________________________
>>>> > > rules-users mailing list
>>>> > > rules-users at lists.jboss.org <mailto:rules-users at lists.jboss.org>
>>>> > > https://lists.jboss.org/mailman/listinfo/rules-users
>>>> <https://lists.jboss.org/mailman/listinfo/rules-users>
>>>> > >
>>>> >
>>>> > _______________________________________________
>>>> > rules-users mailing list
>>>> > rules-users at lists.jboss.org <mailto:rules-users at lists.jboss.org>
>>>> > https://lists.jboss.org/mailman/listinfo/rules-users
>>>> >
>>>> _______________________________________________
>>>> rules-users mailing list
>>>> rules-users at lists.jboss.org <mailto:rules-users at lists.jboss.org>
>>>> https://lists.jboss.org/mailman/listinfo/rules-users
>>>>
>>>>
>>>>
>>>>
>>>>--
>>>>Steven Williams
>>>>
>>>>Supervising Consultant
>>>>
>>>>Object Consulting
>>>>Office: 8615 4500 Mob: 0439 898 668 Fax: 8615 4501
>>>>stevenw at objectconsulting.com.au <mailto:stevenw at objectconsulting.com.au>
>>>>www.objectconsulting.com.au <http://www.objectconsulting.com.au>
>>>>
>>>>consulting | development | training | support
>>>>our experience makes the difference
>>>>------------------------------------------------------------------------
>>>>
>>>>_______________________________________________
>>>>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
>>>
>>>
>>>
>>>
>>>
>>_______________________________________________
>>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
>>
>>
>>
>>
>>
>
>
>
>
--
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
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