- From: Mork, Peter D.S. <pmork@mitre.org>
- Date: Fri, 10 Feb 2006 11:59:24 -0500
- To: <public-semweb-lifesci@w3.org>
>The unstructured-to-structured data effort will deal with how to transform >unstructured (free text), but also semi-structured data sources such as >Excel, XML, Relational db into RDF. 1) RDF is a semi-structured data model itself. 2) A relational database is extremely structured. 3) The difficulty of transforming a semi-structured data-base into an RDF/OWL knowledge-base depends on whether or not the target ontology is pre-specified. For example, transforming a database into OWL is trivial. Every relation is a class, every tuple is an instance of that class. Every attribute of a given tuple is a triple connecting the tuple to its value for that attribute. Transforming arbitrary XML into OWL is described by Sergey Melnik [1]. (Unfortunately, Sergey seems to have lost his Stanford website.) On the other hand, if you have a specific target ontology in mind, then the problem is at least as hard as any semi-structured mapping problem. I say at least as hard because you must decide when to jump formalisms, then solve the integration problem in that formalism. Peter Mork [1] S. Melnik, "Bridging the Gap between RDF and XML," Stanford University Database Group, 1999. http://www-db.stanford.edu/~melnik/rdf/fusion.html
Received on Friday, 10 February 2006 17:01:07 UTC