Interesting that you say its 30-100 times slower, I don't believe we
would be much faster than jess - I'm now very intrigued to look at the
JCHR engine :) with local search leaps wouldn't help as you want to know
all cross products as part of the query. I should have some time early
next year to look over this - are there any obvious things you can say
now? Btw I have taken this conversation to the dev mailing list.
Mark
Peter Van Weert wrote:
Mark Proctor wrote:
Peter,
I believe it is possible to do full prolog style backward chaining,
integrated with standard rules - see
http://wiki.jboss.org/wiki/Wiki.jsp?page=BackwardChaining.
Of course it is possible. Almost every major Prolog distribution (SWI,
XSB, B-Prolog, SICStus 4, YAP, hProlog) includes a port of our CHR
system. These seemingly combine Prolog's backward chaining with CHR's
forward chaining.
I agree that what you are describing on the above wiki page seems to be
a form of backward chaining, something I cannot always say about the
backwards chaining features of other rule engines (Clips, Jess, ...).
I'm interested to see what you mean about performance, with tuning there
should be no reason for our system to be less performant. See email on
dev. I'm willing to apply anything to core that will make this possible.
Geoff when running your examples set the following settings "-Xmx512M
-Xms512M -server", I also believe there is a setting for more
aggressive OO optimisations.
Maybe I should check again. The last time I compared with Drools, it was
still called Drools. We recently did a comparison Jess versus
CHR(hProlog) though, and Jess turned out to be between 30-100 times
slower. This was for one of our benchmarks where the RETE versus Leaps
thing would not even be much of an issue. I suspect that for many other
benchmarks RETE will perform far worse.
Now, let's read the mail on dev. Well, the thing is, if you can still
make improvements of 50%, I think you are not yet there where we are
with CHR. It is becoming more and more difficult to gain more then a few
percents with our highly optimizing compilers (not talking about JCHR
here, because I don't have all optimizations yet). But maybe yes, once
you do more aggressive optimizations and analysis, things could converge.
What's this 'traveling tournament lvl10 use case'? If it is not to big
of a program, I am very interested to port it and see how (J)CHR
performs on it...
Would be truly great if we can work together on a unified system - see
http://markproctor.blogspot.com/2006/11/declarative-behavioural-modelling-dbm.html
Of to bed as I'm shattered, I'll email tomorrow about getting together
online.
Mark
CHeeRs,
Peter
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