W3C home > Mailing lists > Public > public-xg-rdb2rdf@w3.org > July 2008

Re: Follow up on our conference call on 7/11...

From: Kingsley Idehen <kidehen@openlinksw.com>
Date: Wed, 16 Jul 2008 22:15:59 -0400
Message-ID: <487EAB5F.8090204@openlinksw.com>
To: "Ezzat, Ahmed" <Ahmed.Ezzat@hp.com>
CC: "public-xg-rdb2rdf@w3.org" <public-xg-rdb2rdf@w3.org>

Ezzat, Ahmed wrote:
> Hello,
> This is a question that I would be interested in hearing your reaction 
> and views about.
> In a multiple data sources environment where some of them are huge 
> like data warehouses, it seems like transforming all data sources into 
> RDF then querying that RDF store using SPARQL is going to put too much 
> pressure on the RDF store beyond reasonable. In addition all changes 
> in these data sources need to be reflected in the RDF store as soon as 
> possible. In the above paragraph I am ignoring the notion of local and 
> domain Ontologies.
> An alternative I am exploring is to decompose the user query into set 
> of subqueries (SQL and Search) operations to the relevant data sources 
> (i.e., context) ŕ transform the results into RDF using local 
> Ontologies then resolve differences using the domain ontology ŕ apply 
> the SPARQL query on the union of the RDF graphs after reconciliation. 
> Even this approach is far better from RDF storage point of view (i.e., 
> scalability), it seems like response time can be less than desirable?
> Comments and thoughts including additional alternatives…
Ezzat,

All I can say without additional detail is that shouldn't jump to 
conclusions about the scalability of RDF engines re. the warehousing 
approach or the sophistication of SQL optimizers when injected into the 
SQL-RDF mapping realm.

Virtuoso offers solutions for the RDF warehousing and RDF Views 
approaches. I am certainly happy to be proven wrong via experimentation 
re. Virtuoso's ability to handle either approach without compromising 
performance or scalability.

Virtuoso has been designed and engineered to handle heavy duty RDF data 
management (physical or virtual) from the get go.

Please provide me with additional details about database counts and 
sizes etc..


Kingsley

> Regards,
> Ahmed
> /*Ahmed K. Ezzat, Ph.D.*//* */
> *HP Fellow*, *Business Intelligence Software Division
> **Hewlett-Packard Corporation** *
> 19333 Vallco Parkway, MS 4502, Cupertino, CA 95014-2599*
> **Office*: *Email*: _Ahmed.Ezzat@hp.com_ <mailto:Ahmed.Ezzat@hp.com> 
> *Tel*: 408-285-6022 *Fax*: 408-285-1430
> *Personal*: *Email*: _AhmedEzzat@aol.com_ <mailto:AhmedEzzat@aol.com> 
> *Tel*: 408-253-5062 *Fax*: 408-253-6271
>
> ------------------------------------------------------------------------
>


-- 


Regards,

Kingsley Idehen	      Weblog: http://www.openlinksw.com/blog/~kidehen
President & CEO 
OpenLink Software     Web: http://www.openlinksw.com
Received on Thursday, 17 July 2008 02:16:43 GMT

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