[rules-users] RE: fact base storage?

[Greg Barton]

That model sounds quite reasonable.  You may also find it useful to partition your rules by user by having them match on a User object of some kind and user state that matches up with each User.  

rule
when 
  $u : User();
  UserState(user == $u);
  ImmutableFact1(...)
  ImmutableFact2(...)
then 
  ...
end

That way you could have multiple users being processed concurrently and they wouldn't overlap.

--- On Thu, 10/9/08, Evans, Jess <JEvans at collegeboard.org> wrote:

> From: Evans, Jess <JEvans at collegeboard.org>
> Subject: RE: [rules-users] RE: fact base storage?
> To: "Rules Users List" <rules-users at lists.jboss.org>
> Date: Thursday, October 9, 2008, 4:32 PM
> Thanks for the confirmation.  I think it should be
> straightforward to
> implement a parser as you suggest to populate a list of
> java beans and
> assert them to the working memory.  I'm just surprised
> that this doesn't
> already exist.
>  
> May I ask how you manage the working memory?  It looks like
> you can't
> clone or snapshot a working memory.  So, you must either
> assert all the
> default facts in a new working memory for every user
> session/request or
> use a shared synchronized working memory.  I'm building
> a web based
> wizard calculator with around 10k default immutable facts. 
> It's taking
> almost 800ms to assert and fire to reach an initial state,
> so I'm
> planning on sharing one synchronized session.  Is this a
> reasonable
> approach or am I off my rocker?
>  
> Cheers,
>  
> -Jess
> 
> ________________________________
> 
> From: rules-users-bounces at lists.jboss.org
> [mailto:rules-users-bounces at lists.jboss.org] On Behalf Of
> Vikrant
> Yagnick
> Sent: Thursday, October 09, 2008 2:45 PM
> To: Rules Users List
> Subject: [rules-users] RE: fact base storage?
> 
> 
> 
> Hi Jess,
> 
>  
> 
> I am facing the same problem right now. While, I do not
> know of any OOTB
> ways to do this, I initially implemented an all rule
> solution.
> 
> In my case, I had a lookup table that based on a age or
> gender got a
> rate or some value.
> 
>  
> 
> Using some Excel Trickery, I got the 2 dimensional table
> into  one
> dimensional columns of the type:
> 
> Age Gender   Value
> 
> Age and Gender became conditions and Value became the
> Action.
> 
>  
> 
> In your case, you could form a column with a dummy LHS(1=1)
> and keep all
> the columns as Action Columns.
> 
> In each Action Column you could build up your Fact.
> 
>  
> 
> For Example you could do the following:
> 
>  
> 
> Fact{ int a; int b;
> 
> }
> 
> Condition                        Action               
> Action
> 
> F: Fact 
> 
>                                         f.set($1);         
>   f.set($1)
> 
> Eval(true)                        Col A                 
> Col B
> 
> Dummy Value                 <values for a>   
> <values for b>
> 
>  
> 
> If you generate a rule base out of this, it should load
> your tables
> straight as facts.
> 
>  
> 
> However, do note, that I did some rather Q&D benchmarks
> for this and
> soon realized that the rulebase size and memory usage was
> getting really
> large. (Especially the PermGen Size).
> 
>  
> 
> You may want to have a look at the memory usage, in case
> you need to
> load a large number of tables. Due, to the above(and other
> reasons), I
> just wrote a custom parser using JXL (The same Excel
> Library Drools uses
> for Parsing Excels). It is really neat and would make a
> simple solution.
> 
>  
> 
>  
> 
> In, case you get another solution do post it to the list.
> 
>  
> 
> Cheers,
> 
> Vikrant 
> 
>  
> 
>  
> 
>  
> 
>  
> 
>  
> 
>  
> 
>  
> 
> From: rules-users-bounces at lists.jboss.org
> [mailto:rules-users-bounces at lists.jboss.org] On Behalf Of
> Evans, Jess
> Sent: Thursday, October 09, 2008 11:54 PM
> To: rules-users at lists.jboss.org
> Subject: [rules-users] fact base storage?
> 
>  
> 
> I'm trying to come up to speed on the drools
> capabilities.  I see that
> drools supports loading rules from a decision table in a
> spreadsheet.  I
> have a set of conversion tables that I'd like to
> represent as facts
> asserted when the rule base has been loaded, but before
> processing user
> requests.  I could always model lookup tables in a
> database, but I'd
> rather not have to build the CRUD interface to manage them.
>  I'd rather
> represent them so that each row in a spreadsheet represents
> a fact
> (based upon a predefined java bean).  Of course, I could
> custom
> implement this functionality.  However, I was wondering if
> drools
> supports some OOTB means of loading facts from Excel or
> other resource?
> 
>  
> 
> thanks,
> 
>  
> 
> -Jess
> 
>  
> 
> 	
> 
>  
> 
> 
> 
> 
> MASTEK LTD.
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