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[ontolog-forum] Ontology-based database integration

To: "ontolog-forum" <ontolog-forum@xxxxxxxxxxxxxxxx>
From: "Len Yabloko" <lenya@xxxxxxxxxxxxx>
Date: Tue, 06 Oct 2009 18:01:07 +0000
Message-id: <W5198323393142551254852067@webmail2>
Hi Ian,     (01)

Thank you for your reply. I am a huge fan of Chris Partridge's work for a long 
time.     (02)

>Hi Kingsley,
>I think your response raises a question. Was Len looking for ways to simply
>represent relational data in RDF/OWL or was he looking to extract semantics
>from the data ?    (03)

No and no. The first is quite useless and the second is quite impossible. As I 
said - OntoBase is designed to simplify data integration and database 
application development by taking advantage of ontology-based semantic 
modeling. Part of the method used in OntoBase is semi-automatic generation of 
ontology guided by the user, who *is* the main source of semantics. Database 
metadata is used to ensure consistency of the end result and , at the same 
time, to provide automatic translation of the application activity into 
database transactions. None of these goals was ever set or accomplished by the 
above mentioned Semantic Web initiatives.     (04)

> I reckon it's not beyond the wit of most computer scientists
>to cook up a projection from RDBMS to RDF - certainly no more challenging
>than mapping to an OO structure, and that's been done for years (tools to
>re-engineer SQL databases into CORBA/COM APIs have been around for ages).
>Some projections offer better performance / usability than others, but
>that's the only aspect that's really open for innovation. 
>    (05)

To be fare to Semantic Web community - they have set and accomplished some 
significant goals that were never reached by CORBA and other model-based 
initiatives (MDA, MDD etc). Feasible reasoning with DL and incorporating rules 
into query languages. Bu the main source of confusion is that Semantic Web 
technologies do no replace modeling technologies and do not solve the same 
problems.     (06)

>Trying to automatically extract semantics from RDBMS is herring of an
>altogether different colour. Several people claim to be able to do this, but
>having looked at some of the results I've got to say their view of
>"semantic" sets a far lower bar than mine.    (07)

Fully agree. As usual there is a hype and ignorance on part of IT marketeers. 
But you can't blame them for doing their job. Some of them are still selling 
XML as data integration platform. I guess they will continue for as long as 
there is someone who pays for that.     (08)

>I even had an academic try to
>reject a conference paper on legacy data re-engineering I'd written on the
>basis that my work was redundant because his system did it all
>automatically. That's nearly two years ago. I fully expected he'd be a
>billionaire by now. 
Some are! This is the nature of marketing which is legal (in best case) 
deception of ignorant. I might add - with the help of those not willing to 
admit to ignorance for a fear or loosing their job.     (09)

>I spent years mapping legacy data into "semantically richer" formats such as
>ISO10303 (ok, maybe not much richer) and ISO15926, and it always comes down
>to the data, not the data model. You can guarantee the data modeller got it
>wrong when they built the system, and the users have been working against
>rather than with the model for years. Unless you have a good sniff around in
>the data, you'll never get a real picture of the true semantics (i.e. what
>the data is actually referring to in the real world). That's certainly the
>case for production systems that have been in use for some time (by real
>users, not students faking data). I wrote a paper for Cutter on this
>recently - http://www.cutter.com/offers/forensicIS.html.
>    (010)

The project I do for DoD calls this process Semantic Model Discovery. Actually, 
there are many models some times used in turns, and they all are evolving. They 
main goal of data integration should be maintaining consistent mapping between 
different semantic models. The main challenge is to define what "consistent" 
means. This where Chris Partridge's work first opened my eyes on true mature of 
semantics, as opposed to mathematical notion of 1st order logic some times 
confused with semantics (I know this statement will provoke discussion)    (011)

>I never had a formal method for re-engineering data in those days. In recent
>years I've been using Chris Partridge's BORO Method. It seems to work pretty
>well as far as I can tell. Don't tell him I said that though.    (012)

Why not?!    (013)

>    (014)

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