On Thu, 2007-11-29 at 08:14 -0500, John S. Erickson wrote: > Richard Rodgers wrote: > > (1) There is a lot of metadata in DSpace (and a lot more to come) that is > > not related to user discovery (technical metadata, e.g) - this could live > > in a triple store - but would not benefit from it. In fact, a lot or > > record-based metadata is accessed much more efficiently in a RDBMS. > > 1. From an architectural standpoint, doesn't a triple store (in theory) > make it fundamentally easier to deal with a diversity of metadata types, > *especially* technical metadata --- which can vary not only between > formats but even between instances of a given format, depending upon the > applications that have modified the bitstreams?
Yes absolutely, but what I was trying to question was the 'grand unification' assumption I think gets made implicitly or explicitly in these discussions: i.e. that there has to be a single way DSpace represents and manages all its metadata. Since RDF is so general/powerful, it always looks like the prohibitive favorite if framed in these terms. I picture a continuum - which ranges from completely 'dark' metadata living only in an AIP in the asset store (recoverable, of course) to highly visible discovery metadata - with copies in Lucene, a triple-store, Google caches, etc. and cases in between involving collection management. Where Longwell/RDF shines is the case where such heterogeneous metadata needs to be combined for a particular discovery purpose. Now as Christophe pointed out, the trick is to manage this spectrum without excess system complexity, and too many moving parts. > > 2. Regarding efficiency, are you referring to query (somehow harder to > get what you want) or performance (triple-store implementations haven't > benefited from 30+ years of refinement)? More query than absolute scalability - I agree that triple-store implementations scale to at least relational database levels (often because they are backed by relational DBs!). And performance depends on the typical contexts of use - which gets back to point I was making above about different functional uses of metadata. > > Just trying to provoke discussion ;) You succeeded ;) Richard > > John > > ------------------------------------------------------------------------- > SF.Net email is sponsored by: The Future of Linux Business White Paper > from Novell. From the desktop to the data center, Linux is going > mainstream. Let it simplify your IT future. > http://altfarm.mediaplex.com/ad/ck/8857-50307-18918-4 > _______________________________________________ > DSpace-tech mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/dspace-tech ------------------------------------------------------------------------- SF.Net email is sponsored by: The Future of Linux Business White Paper from Novell. From the desktop to the data center, Linux is going mainstream. Let it simplify your IT future. http://altfarm.mediaplex.com/ad/ck/8857-50307-18918-4 _______________________________________________ DSpace-tech mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/dspace-tech
