- From: Dan Brickley <Daniel.Brickley@bristol.ac.uk>
- Date: Sat, 8 Jan 2000 11:05:01 +0000 (GMT)
- To: heiko.grussbach@crpht.lu
- cc: www-rdf-interest@w3.org
On Fri, 7 Jan 2000 heiko.grussbach@crpht.lu wrote: > Hi, > > I remember a few months ago, there was a discussion on how to store RDF in > relational databases. Does anybody have experience or ideas on how to store > RDF in object-relational or pure object-oriented databases? I don't have a general answer, but you might find the Ozone database worth a look. I've just (like, as I type) started to play with this as a possible way of persisting RDF objects. It's pure Java, Open Source and has well documented installation instructions. Beyond that I'll let you know how my experiments go when I've actually done something with my new installation... Ozone is of the 'persistant java classes' school of OO databasery; ie. there is no query language so we don't get to look at issues of mapping RDF query to object database queries. (excerpt from docs) A second point is the integration of ozone in Java. There is no special query language and no interface definition language. The database scheme is generated from the Java byte code. All queries are simple Java methods. Database classes are derived from a ozone class or support a specific interface. Beyond that the programming of database classes doesn't differ from the programming of normal classes. Given an in-memory RDF graph, this would give one way of stashing it on disk OOdb style. The Ozone site contains more information on 'ozoneXML' where they've done exactly this for the XML DOM API. Naively, I'm thinking that if it works for DOM it should work for RDF apps too. Performance would be another matter though. The site claims that their DOM implementation "gives us the possibility to do highly optimized queries on plain DOM structures.". If anyone has more experiment of Ozone and ozoneXML in practice, do tell... Ozone is at http://www.ozone-db.org/ Dan
Received on Saturday, 8 January 2000 06:06:09 UTC