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RE: SWAD-Europe Report: Mapping Semantic Web Data with RDBMSes

From: Wagner,Harry <wagnerh@oclc.org>
Date: Sun, 2 Feb 2003 11:06:26 -0500
Message-ID: <90D12689EF7A0543AB11426D75D6ABC51D54A7@oa4-server.oa.oclc.org>
To: www-rdf-interest@w3.org, "'Prajakta.Nivargi@asu.edu'" <Prajakta.Nivargi@asu.edu>

Hi Prajakta,

---
I am trying to create a registry of different models. There will be
different 
namespaces. Can this be represented using the RDBMSs like JENA and the
others 
mentioned in this article?

Also , by the storage mechanism described in the article, is it possible to 
search the database for a particular resource? i.e. a model based search?
---

The answer to your questions is yes.  The DCMI metadata registry
(http://dublincore.org/dcregistry/index.html) was built using Jena and
PosgreSQL.  

My own experiences with RDF and RDBMS have been mixed.  They do work
together, but require a bit more work than more traditional applications in
order to maintain a reasonable level of performance.  The reason is the
limited options for indexing.  For example: a tradional (by this I mean
non-RDF) application that will access data in a RDB by zip code would
typically build an index on the zip code column.  This is not really an
option with RDF since 'zip code' would be just another statement.  The trick
with RDF seems to be to split the data between several databases or build
'pointers', using application code, during the data load.

Have you looked at BerkelyDB?  The performance improvement over RDBMS is
significant.

Regards... harry


Quoting Dave Beckett <dave.beckett@bristol.ac.uk>:

> 
> 
>   Report on Mapping Semantic Web Data with RDBMSes
>  
> http://www.w3.org/2001/sw/Europe/reports/scalable_rdbms_mapping_report/
> 
>   for Semantic Web Advanced Development Europe (SWAD-Europe) project
>       http://www.w3.org/2001/sw/Europe/
>       funded by the EU IST-7 programme IST-2001-34732.
> 
>   Authors: Dave Beckett, Jan Grant
> 
>   Abstract:
>     A public report on mapping triple stores and RDBMS concentrating
>     on surveying the schemas used and discussing mapping approaches
>     to and from relational schemas. It describes current best
>     practice for using such systems for Semantic Web data including
>     feature comparisons, recommendations for particular applications
>     and advice on tradeoffs.
> 
> 
> We've tried to address:
>    1. I want to implement an RDF triple store. How can I do this with
>       a relational database?
> 
>    2. I have a legacy relational database. How can it be exposed as
> RDF?
> 
> 
> We welcome feedback either directly or on our public mailing lists
> and intend to update this over the lifetime of the project as we
> develop new approaches and in line with changes to tools.
> 
> Dave
> 
> 
Received on Sunday, 2 February 2003 14:36:03 GMT

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