Best bet is to jump on #drools on irc.codehaus.org when you get a chance, we can talk you though the design of drools 3 (and what is different with drools 2 in that regard).
On 3/9/06, Mitch Christensen <[EMAIL PROTECTED]> wrote: > > My question is not really about java, but the implementation of the Rete > network. > > Rete implementations typically have a pattern network and a join network. > The pattern network is responsible for matching constants and > 'intra-condition' variable references. The join network is responsible > for > variable references across conditions. Typically processing within the > pattern network is much more efficient than the join network. > > Back to my original example, by testing each object property separately I > create two conditions, hence two nodes in the pattern network. By > creating > a single comparison function, I reduce this to one condition/pattern node. > This may seem like '6 of one, half dozen of the other', but what if my > test > object has 10 properties? Would it be better to have 10 conditions in my > rule, or create a comparison method and have only one condition? > > It seems to me that in order to facilitate pattern sharing (one of the > stated benefits of the Rete network) the use of more, simple conditions > might be better. > > This whole thought process was triggered by a posting a few days back > regarding building 'human readable' rules through the effective crafting > of > Java methods on the test objects. I started to wonder what the impact of > this would be to pattern matching within the Rete engine, which leads me > to > realize that I really didn't understand how pattern matching works in > Drools. > > The general concept of differentiating between the pattern and join > networks > also has relevance to some work that is happening on my current project. > > Thanks. > -Mitch > > -----Original Message----- > From: Michael Neale [mailto:[EMAIL PROTECTED] > Sent: Tuesday, March 07, 2006 3:43 PM > To: user@drools.codehaus.org > Subject: Re: [drools-user] Structuring conditions, alpha and beta networks > > The former would be more efficient, just as in java code. Its comparing to > identies (integer comparison) versus a method call. > > (assuming the results are the same). > > On 3/8/06, Mitch Christensen <[EMAIL PROTECTED]> wrote: > > > > Hey, > > > > If I have a Java bean with two properties, p1 and p2 and want to have a > > rule > > that processes matching beans, which set of patterns is 'better' as far > as > > Drools is concerned? > > > > Assuming, > > > > <parameter identifier='b1'><class>MyBean</class></parameter> > > <parameter identifier='b2'><class>MyBean</class></parameter> > > > > Then would > > > > <java:condition>b1.getP1() == b2.getP1()</java:condition> > > <java:condition>b1.getP2() == b2.getP2()</java:condition> > > > > OR > > > > <java:condition>b1.equals(b2)</java:condition> > > > > (assuming I've properly implemented equals()) > > > > Be more appropriate? > > > > Are there any performance implications between the two? > > > > My experience with other Rete implementations is that the alpha network > > performs constant tests. In Drools, I'm having a hard time visualizing > > the > > difference between what the alpha and beta portions of the network will > be > > processing. > > > > It seems to me that the alpha portion of the network should be > responsible > > for the parameter identification (is this true?), if so, does it also > > apply > > to conditions, and if so, to what extent? > > > > I have read most (if not all) of the Drools documentation and still > > struggle > > a bit understanding how this works. > > > > Any help or pointers to good documentation would be appreciated. > > > > Thanks. > > -Mitch > > > > > > > > >
