Re: [rules-users] Convert logic to DRL rules

Mon, 19 Feb 2007 12:59:16 -0800 


  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: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] 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: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] 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 <[EMAIL PROTECTED]> 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* <[EMAIL PROTECTED]
<mailto:[EMAIL PROTECTED]>> 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 < [EMAIL PROTECTED]
  <mailto:[EMAIL PROTECTED]>> 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 < [EMAIL PROTECTED]
  <mailto:[EMAIL PROTECTED]>> 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 <[EMAIL PROTECTED]
  <mailto:[EMAIL PROTECTED]>> 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:
  > >> [EMAIL PROTECTED],1040:1041='<=',<47>,39:40];
  > >> > expecting type '('
  > >> > unknown:39:92 mismatched token:
  > >> [EMAIL PROTECTED],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 <[EMAIL PROTECTED]
  <mailto:[EMAIL PROTECTED]>> wrote:
  > >> > > Thank you Steve. But I got syntax error using the

following.



  > >> > >
  > >> > > On 2/17/07, Steven Williams
  <[EMAIL PROTECTED]
  <mailto:[EMAIL PROTECTED]>> 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 < [EMAIL PROTECTED]
  <mailto:[EMAIL PROTECTED]>> 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
  > >> > > > > [email protected]
  <mailto:[email protected]>
  > >> > > > >
  > >> https://lists.jboss.org/mailman/listinfo/rules-users
  > >> > > > >
  > >> > > >
  > >> > > >
  > >> > > >
  > >> > > > --
  > >> > > > Steven Williams
  > >> > > >
  > >> > > > Supervising Consultant
  > >> > > >
  > >> > > > Object Consulting
  > >> > > > Office: 8615 4500 Mob: 0439 898 668 Fax: 8615 4501
  > >> > > > [EMAIL PROTECTED]
  <mailto:[EMAIL PROTECTED]>
  > >> > > > www.objectconsulting.com.au
  <http://www.objectconsulting.com.au>
  > >> > > >
  > >> > > > consulting | development | training | support
  > >> > > > our experience makes the difference
  > >> > > > _______________________________________________
  > >> > > > rules-users mailing list
  > >> > > > [email protected]
  <mailto:[email protected]>
  > >> > > > https://lists.jboss.org/mailman/listinfo/rules-users
  > >> > > >
  > >> > > >
  > >> > >
  > >> > _______________________________________________
  > >> > rules-users mailing list
  > >> > [email protected]
  <mailto:[email protected]>
  > >> > https://lists.jboss.org/mailman/listinfo/rules-users
  > >> >
  > >>
  > >>
  > >>
  > >> --
  > >> Steven Williams
  > >>
  > >> Supervising Consultant
  > >>
  > >> Object Consulting
  > >> Office: 8615 4500 Mob: 0439 898 668 Fax: 8615 4501
  > >> [EMAIL PROTECTED]
  <mailto:[EMAIL PROTECTED]>
  > >> www.objectconsulting.com.au

<http://www.objectconsulting.com.au>



  > >>
  > >> consulting | development | training | support
  > >> our experience makes the difference
  > >> _______________________________________________
  > >> rules-users mailing list
  > >> [email protected]

<mailto:[email protected]>



  > >> https://lists.jboss.org/mailman/listinfo/rules-users
  > >>
  > >>
  > > _______________________________________________
  > > rules-users mailing list
  > > [email protected] <mailto:[email protected]>
  > > https://lists.jboss.org/mailman/listinfo/rules-users
  <https://lists.jboss.org/mailman/listinfo/rules-users>
  > >
  >
  > _______________________________________________
  > rules-users mailing list
  > [email protected] <mailto:[email protected]>
  > https://lists.jboss.org/mailman/listinfo/rules-users
  >
  _______________________________________________
  rules-users mailing list
  [email protected] <mailto:[email protected]>
  https://lists.jboss.org/mailman/listinfo/rules-users




--
Steven Williams

Supervising Consultant

Object Consulting
Office: 8615 4500 Mob: 0439 898 668 Fax: 8615 4501
[EMAIL PROTECTED] <mailto:[EMAIL PROTECTED]>
www.objectconsulting.com.au <http://www.objectconsulting.com.au>

consulting | development | training | support
our experience makes the difference
------------------------------------------------------------------------

_______________________________________________
rules-users mailing list
[email protected]
https://lists.jboss.org/mailman/listinfo/rules-users


_______________________________________________
rules-users mailing list
[email protected]
https://lists.jboss.org/mailman/listinfo/rules-users


_______________________________________________
rules-users mailing list
[email protected]
https://lists.jboss.org/mailman/listinfo/rules-users
_______________________________________________
rules-users mailing list
[email protected]
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
[email protected]
https://lists.jboss.org/mailman/listinfo/rules-users

Reply via email to