- From: Michael Hausenblas <michael.hausenblas@deri.org>
- Date: Fri, 05 Feb 2010 08:24:32 +0000
- To: <ashok.malhotra@oracle.com>, Richard Cyganiak <richard.cyganiak@deri.org>
- CC: RDB2RDF WG <public-rdb2rdf-wg@w3.org>
Ashok, You sent this mail to the wrong list (that is to the old XG list ;) hence Richard didn't receive it. I've now forwarded it to the correct list. You might want to update your address book with: RDB2RDF WG <public-rdb2rdf-wg@w3.org> Cheers, Michael -- Dr. Michael Hausenblas LiDRC - Linked Data Research Centre DERI - Digital Enterprise Research Institute NUIG - National University of Ireland, Galway Ireland, Europe Tel. +353 91 495730 http://linkeddata.deri.ie/ http://sw-app.org/about.html > From: ashok malhotra <ashok.malhotra@oracle.com> > Organization: Oracle > Reply-To: <ashok.malhotra@oracle.com> > Date: Tue, 02 Feb 2010 15:05:59 -0800 > To: Richard Cyganiak <richard@cyganiak.de>, RDB2RDF XG list > <public-xg-rdb2rdf@w3.org> > Subject: Discussion on today's telcon > Resent-From: RDB2RDF XG list <public-xg-rdb2rdf@w3.org> > Resent-Date: Tue, 02 Feb 2010 23:07:01 +0000 > > Hi Richard: > I'm thinking about the discussion we had on the telcon this morning and > I have a couple of questions. > > Let us agree on the premise that MySQL does a poor job of optimizing SQL > queries that contain > subqueries and that using such views would entail a serious performance hit. > You said that the R2RQ approach helps rewrite such queries in a form > that is more performant. > Could you give us an example of how it does that? > > Second, suppose we go with the SQL-View approach could we not add a > Informative Note that > said "If you are using MySQL and your view has one or more subqueries in > it then you may take > a performance hit. We suggest that you rewrite the view in the > following manner ..." > Does that make sense? > -- > All the best, Ashok >
Received on Friday, 5 February 2010 08:25:10 UTC