- From: Adrian Walker <adrianw@snet.net>
- Date: Mon, 15 Nov 2004 09:45:32 -0500
- To: Eric Jain <Eric.Jain@isb-sib.ch>
- Cc: www-rdf-interest@w3.org
Eric -- One way of storing context info, while keeping triples as the main representation, is to make use of the tuple IDs assigned by Oracle and most DBMSs**. So, the main table would have the magic number 3 columns, but there would be a hidden ID number for each triple. An auxiliary table would then store provenance info keyed by tuple ID, or by range of tuple IDs. Of course, in DBMSs that don't provide this, one can simply use four columns for the main table, the first of which is would be tuple ID. HTH, -- Adrian ** However, my limited understanding is that DB2 row IDs are unsuitable for this purpose. INTERNET BUSINESS LOGIC (R) www.reengineeringllc.com Dr. Adrian Walker Reengineering LLC PO Box 1412 Bristol CT 06011-1412 USA Phone: USA 860 583 9677 Cell: USA 860 830 2085 Fax: USA 860 314 1029 At 09:42 AM 11/15/2004 +0100, you wrote: >Danny Ayers wrote: >>I've often had doubts, but haven't yet really encountered any >>situation for which the lack of RDF contexts/quads has been a killer. > >Here is my use case: > >We have a lot of documents each of which consists of several hundred >statements. Every document has some metadata such as when it was last >revised. This information can easily be indicated when such a document is >stored in a single file, using rdf:about="". The other solution of course >would be to reify all statements, which is definitely not practical (which >is not to say that reification isn't useful for making assertions about >individual statements). > >The important point is that I can no longer make use of this metadata >after loading the data into an RDF database (e.g. retrieve a set of >statements or search only statements that are available under a license >that allows non-commercial use), unless the database supports some kind of >context. > >I would be quite surprised if I were the only person on this planet with >this problem... > > >>context can be done in a way that is RDF-friendly and useful without >>needing quads though - check the good Mr. Beckett's approach in >>Redland: > >For all I can tell he *is*, in principal, using quads, isn't he? > > graph.add(triple, identifier) >
Received on Monday, 15 November 2004 14:45:57 UTC