[Top] [All Lists]

Re: [ontolog-forum] Next steps in using ontologies as standards

To: "[ontolog-forum]" <ontolog-forum@xxxxxxxxxxxxxxxx>
From: "John F. Sowa" <sowa@xxxxxxxxxxx>
Date: Tue, 20 Jan 2009 17:29:04 -0500
Message-id: <49765030.3050609@xxxxxxxxxxx>
Pat,    (01)

I fully approve of having a very simple tuple-based notation as
the foundation.    (02)

PH> I still think that RDF is at heart a good idea: a very basic,
 > simple, notational/semantic foundation level that one can learn
 > in an afternoon and write simple applications for in a few days.    (03)

Google also approves of that idea, but they don't use RDF or OWL
for the obvious reasons.  Instead, they use JSON (JavaScript Object
Notation), which supports arbitrary N-tuples in a notation that
is very readable for humans and far more compact than RDF for its
internal form.  Furthermore, they also integrate their technology
with relational databases.    (04)

PH> The only 'we' who are going to do this are W3C working groups.
 > If you want to convene one, you have to do it yourself or persuade
 > someone to do it for you.    (05)

Google is doing things right.  I have a preference for open standards
rather than proprietary systems, and I hope that people who develop
standards pay attention to what Google is doing:    (06)

    http://code.google.com/apis/gears/tutorial.html    (07)

PH> Just moaning on this or any other email forum isn't going to get
 > it done.    (08)

I'm not moaning.  I'm telling people that Google is on the right
track, and the current Semantic Web is not.  I'm betting on Google.    (09)

PH> [First-order logic] doesn't apply to the actual information
 > [in a relational DB], only the query, and its not full FOL there
 > because the quantifiers are all finite.    (010)

Several points:    (011)

  1. The RDB tables can be viewed as *either* a set of ground-level
     assertions *or* as a model (in Tarski's sense), in terms of
     which the statements in the WHERE clause are evaluated.    (012)

  2. It is true that no stored relations can be infinite.  But
     SQL syntax also supports virtual relations, such as less-than
     or arithmetical computations, which can have the effect of
     being infinite.    (013)

  3. The WHERE clause has multiple uses.  The original use was
     for queries, but they also use it to support constraints on
     updates.  The time to evaluate the WHERE expression in terms
     of a collection of ground-level clauses takes polynomial time
     (or faster with indexed fields).    (014)

  4. My preferred notation for RDB WHERE clauses is Datalog, which
     has a cleaner notation than SQL.  It also supports either
     classical negation or negation as failure.    (015)

PH> ... the implementors loved triple store technology (which still
 > runs way faster than DB tables when you have a large enough RAM...    (016)

Several more points:    (017)

  1. Any processing done in RAM is faster than anything paged from
     rotating storage.  But that has absolutely nothing to do with
     the choice between triples and N-tuples.    (018)

  2. The single most important optimization is to implement indexes
     over the tuples.  Every major RDB has excellent indexing
     technology, and a triple store without indexing is a dog in
     comparison.  (There are horror stories about large companies
     and gov't agencies that converted their RDBs to RDF with
     absolutely disastrous results.)    (019)

  3. The most sophisticated graph processing technology has *not*
     been developed by the comp. sci. gang, but by the chemists,
     who have very large graphs to store and process.  They don't
     use triple stores because they are incredibly slow and naive
     for complex operations.  We do very sophisticated graph
     processing at VivoMind, and we follow the chemists, not the
     poor benighted losers who suffer with triple stores.    (020)

Triple stores are just one more example where some intelligent,
but ignorant implementers persuaded a large group of people who
didn't do their homework to adopt dead-end technology.    (021)

Unless the people at the W3C wise up, I'm betting on Google.    (022)

John    (023)

Message Archives: http://ontolog.cim3.net/forum/ontolog-forum/  
Config Subscr: http://ontolog.cim3.net/mailman/listinfo/ontolog-forum/  
Unsubscribe: mailto:ontolog-forum-leave@xxxxxxxxxxxxxxxx
Shared Files: http://ontolog.cim3.net/file/
Community Wiki: http://ontolog.cim3.net/wiki/ 
To join: http://ontolog.cim3.net/cgi-bin/wiki.pl?WikiHomePage#nid1J
To Post: mailto:ontolog-forum@xxxxxxxxxxxxxxxx    (024)

<Prev in Thread] Current Thread [Next in Thread>