[rules-users] rule using sliding window

[Edson Tirelli]

   In order to keep the rules cleaner and easier to maintain, I prefer to
hide the details of the database loading (query, etc) behind a helper method
with a clear contract. But up to you.

   []s
   Edson

2009/6/2 Bhushan Bhangale <bhushan_bhangale at kaleconsultants.com>

>  Thanks Edson
>
>
>
> I read about “from” CE and understand that it can call any external method.
> In the external method I can write the code to extract the data from
> database.
>
>
>
> I googled and found this, where its using hibernate session and that way
> giving complete flexibility in writing rule on any data set. Do you think
> it’s a good idea?
>
>
>
> global org.hibernate.Session hibernateSession;
>
>
>
> rule "hibernate_from"
>
>             when
>
>                         game:Game() from
> hibernateSession.createQuery("select games from Player p where p.age >=
> :age").setProperties( {"age" : 18 }).list()
>
>             then
>
>                         System.out.println("The game "+game.getName() +"is
> owned by "+game.getPlayers());
>
> end
>
>
>
>
>
> -----Original Message-----
> *From:* rules-users-bounces at lists.jboss.org [mailto:
> rules-users-bounces at lists.jboss.org] *On Behalf Of *Edson Tirelli
> *Sent:* Monday, June 01, 2009 6:48 PM
> *To:* Rules Users List
> *Subject:* Re: [rules-users] rule using sliding window
>
>
>
>
>    Hi
>
>    The description you have bellow is ambiguous, so I can't give you a
> definitive answer. But it seems to be that you don't need sliding windows
> for that. Simple temporal operators will do.
>
> > Secondly if the window is large and number of records coming in is high
> then could there be a memory issue?
>    Yes, Drools does not manages persistence by itself. So, if your design
> must support more data than it would fit in your running environment memory,
> you need to design a solution that comprises persistence.
>
> > Also since every record is getting stored in database, can I not use the
> database directly instead of sliding window?
>    Yes, you can fetch data on demand from external sources, be it databases
> or anything else. Look at the "from" CE.
>
>     []s
>     Edson
>
>  2009/6/1 Bhushan Bhangale <bhushan_bhangale at kaleconsultants.com>
>
> I am using Drools 5. I am struggling to write rule for this logic -
>
> If a stock price changes more than 10% within an hour then report the
> change.
>
> I understand I have to use sliding window feature but unable to write the
> rule.
>
> For example I got an update for IBM stock @ 12:30 for price 100 and then
> another update IBM stock @ 12:35 for price 111. Since the time difference is
> within an hour and the change is also greater than 10% I want to report this
> price change.
>
>
>
> Stock class -
>
>
>
> Public class Stock {
>
>    Private String stock;
>
>    Private double price;
>
>    Private Date time;
>
>    Private double priceChange;
>
>    Private Boolean highlight;
>
> }
>
>
>
>
>
> rule "Stock Price change more than 10% within an hour"
>
>
>
> when
>
>
>
> then
>
> set the priceChange attribute of Stock object
>
> set highlight to true
>
> end
>
>
>
>
>
> Secondly if the window is large and number of records coming in is high
> then could there be a memory issue?
>
>
>
> Also since every record is getting stored in database, can I not use the
> database directly instead of sliding window?
>
>
>
> Thanks
>
>
>
> *Mr. Bhangale Bhushan*
> *Associate Manager*
> *Kale Consultants Ltd.*
> bhushan_bhangale at kaleconsultants.com
> tel: +91 (0)206 608 3777<http://www.plaxo.com/click_to_call?lang=en&src=jj_signature&To=%2B91+%280%29206+608+3777&Email=bhushan_bhangale@kaleconsultants.com>
> http://www.kaleconsultants.com
>
>
>
>
>
>
>
>
>
>
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>
> --
>  Edson Tirelli
>  JBoss Drools Core Development
>  JBoss, a division of Red Hat @ www.jboss.com
>
> Disclaimer: This email (including any attachments) is intended for the sole
> use of the recipient/s and may contain material that is CONFIDENTIAL. Any
> unauthorized disclosure / copying / distribution or forwarding of this message
> or part is STRICTLY PROHIBITED. If you have erroneously received this message,
> please delete it immediately and notify the sender. No liability is assumed for
> any errors and/or omissions in the contents of this message. Information in
> this message that does not relate to the official business of this Company
> shall be understood as neither given nor endorsed by it. If verification is
> required please request a hard-copy version.
>
> To know more about Kale Consultants, visit www.kaleconsultants.com
>
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-- 
 Edson Tirelli
 JBoss Drools Core Development
 JBoss, a division of Red Hat @ www.jboss.com
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