Hello John, (01)
On Fri, Oct 12, 2012 at 11:49:03AM -0400, John F Sowa wrote:
> Fundamental issue: Tim B-L emphasized three basic principles in
> the DAML proposal of Feb 2000: interoperability, diversity, and
> heterogeneity. He said that SWeLL (a superset of propositional
> logic, first-order logic, and higher-order logic) was necessary
> to support all the heterogeneous systems on the WWW. He also
> mentioned KIF and SQL as languages that had to be supported. (02)
SQL is supported. There are products that offer SQL views over triple
stores. The query language may not be the problem. Performance and difficulty
of modeling data are. (03)
> > Triples only offer complex modeling that is potentially slow and
> > potentially bad (relations should have higher arity). But probably modeling
> > higher arity relations with lower arity relations is not so bad as modeling
> > lower arity relations with higher arity relations.
>
> That's an implementation issue that is independent of the way you
> present the data to users or to application programs. (04)
I don't think performance of triples vs. n-tuples is an implementation issue. (05)
> Stonebraker
> demonstrated that in an extremely fast implementation of VoltDB:
> Source:
>
>http://highscalability.com/blog/2010/6/28/voltdb-decapitates-six-sql-urban-myths-and-delivers-internet.html
> > VoltDB claims to be 100 times faster than MySQL, up to 13 times faster than
> > Cassandra, and 45 times faster than Oracle, with near-linear scaling. (06)
No wonder it is so fast if all the data is in RAM and - let me quote from the
document - "You are also discouraged from doing SUM operations". (07)
> > The binary has_name property stands on its own and should clearly not be
>part
> > of another relation with higher arity but doing it so makes things faster.
>
> There are many kinds of tradeoffs for various purposes. (08)
And my point about triples vs. n-tuples was that the user would be able to
choose between tradeoffs with n-tuples. I think we both agree that it would be
nice if the Semantic Web stack would offer more choices. But ranting about
missing choices is much easier than implementing them. Let's see what
the people outside W3C come up with in the future. Right now I cannot see
alternatives to RDF for representation and exchange of heterogenous knowledge.
The SMW data structures you pointed out are internal. What is used for
publishing the data is RDF. (09)
Regards, (010)
Michael Brunnbauer (011)
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