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RE: Performance issues with OWL Reasoners => subclass vs instance-of

From: Kashyap, Vipul <VKASHYAP1@PARTNERS.ORG>
Date: Mon, 18 Sep 2006 13:47:02 -0400
Message-ID: <2BF18EC866AF0448816CDB62ADF6538104C1656A@PHSXMB11.partners.org>
To: "Phillip Lord" <phillip.lord@newcastle.ac.uk>, "Chimezie Ogbuji" <ogbujic@bio.ri.ccf.org>
Cc: "William Bug" <William.Bug@drexelmed.edu>, "chris mungall" <cjm@fruitfly.org>, <semantic-web@w3.org>, "w3c semweb hcls" <public-semweb-lifesci@w3.org>



>   CO> Once again: pure production/rule-oriented systems *are* built to
>   CO> scale well in *all* circumstances (this is the primary advantage
>   CO> they have over DL reasoners - i.e., reasoners tuned specifically
>   CO> to DL semantics).  This distinction is critical: not every
>   CO> reasoner is the same and this is the reason why there is
>   CO> interest in considerations of using translations to datalog and
>   CO> other logic programming systems (per Ian Horrocks suggestion
>   CO> below):
> 
> Well, as I am speaking at the limit of my knowledge I cannot be sure
> about this, but I strongly suspect that what you say is wrong.

[VK] I share the "suspicions" of Phil in this regard. I doubt if rule based
reasoners can perform uniformly well and scale in all conditions.

My agreement with Chimezie is limited to the scalability of ABox reasoning.
Looks like there are two possibilities to scale ABox reasoning:
1. SQL+DL (Tableaux?) reasoning
2. Rule based approach

>   CO> I'd go a step further and suggest that even large terminologies
>   CO> aren't a problem for such systems as their primary bottleneck is
>   CO> memory (very cheap) and the complexity of the rule set. The set
>   CO> of horn-like rules that express DL semantics are *very* small.

> Besides, what is the point of suggesting that large terminologies
> are not a problem? Why not try it, and report the results?

[VK] I am not sure whether rules-based approaches will scale for TBox reasoning.
It may be noted that earlier approaches for implementing DL reasoners, based on
rule based approaches which did not scale very well.
In fact the tableaux technique is supposed to be more efficient than earlier
DL reasoners. So it is unlikely that implementing DL semantics in
a rule based system will scale better than current approaches pointed out by
Ian Horrocks, viz., restricting the complexity (CEL) or optimization for typical
cases.

In any case, as Phil would suggest, the best thing is to experiment with it and
report the results.

Cheers,

---Vipul
Received on Monday, 18 September 2006 17:47:44 UTC

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