[rules-users] RE: fact base storage?

[Evans, Jess]

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.
Mastek is in NASSCOM's 'India Top 20' Software Service Exporters List.
In the US, we're called MAJESCOMASTEK

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Opinions expressed in this e-mail are those of the individual and not
that of Mastek Limited, unless specifically indicated to that effect.
Mastek Limited does not accept any responsibility or liability for it.
This e-mail and attachments (if any) transmitted with it are
confidential and/or privileged and solely for the use of the intended
person or entity to which it is addressed. Any review, re-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. This e-mail and its attachments have been
scanned for the presence of computer viruses. It is the responsibility
of the recipient to run the virus check on e-mails and attachments
before opening them. If you have received this e-mail in error, kindly
delete this e-mail from desktop and server.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
	
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.jboss.org/pipermail/rules-users/attachments/20081009/51f3e12a/attachment.html