- From: Kingsley Idehen <kidehen@openlinksw.com>
- Date: Thu, 17 Jul 2008 00:50:11 -0400
- To: "Ezzat, Ahmed" <Ahmed.Ezzat@hp.com>
- CC: "public-xg-rdb2rdf@w3.org" <public-xg-rdb2rdf@w3.org>
Ezzat, Ahmed wrote: > I am not up to speed to what Virtuoso do, i.e., I do not know if what Virtuoso do will work in my scenario. > > But a data warehouse in our environment is 100+ TB which would be considered one data source in the enterprise. Do you see converting that size of data into RDF (i.e., as described in my first approach) as viable? > It can be converted, this is a data center matter if warehousing is the ultimate solution. But, I wouldn't take the warehousing route if I can create RDF Views of the SQL Data :-) Our RDB to RDF mapping is all about using SQL optimization heuristics to deliver high-performance and scalable RDF Views of SQL Data. I am confident with an appropriately configured data center plus Virtuoso Cluster Edition using RDF Views or RDF warehousing your challenge is addressable. In our tests with the TPC-H benchmark, we've been able to get RDF Views to outperform RDF warehousing, so warehousing is purely a last resort option at best. Kinglsey > Ahmed > > -----Original Message----- > From: Kingsley Idehen [mailto:kidehen@openlinksw.com] > Sent: Wednesday, July 16, 2008 7:16 PM > To: Ezzat, Ahmed > Cc: public-xg-rdb2rdf@w3.org > Subject: Re: Follow up on our conference call on 7/11... > > 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) à transform the results into RDF using local >> Ontologies then resolve differences using the domain ontology à 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 > > > > > > -- 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 04:50:52 UTC