- From: ashok malhotra <ashok.malhotra@oracle.com>
- Date: Tue, 02 Feb 2010 15:05:59 -0800
- To: Richard Cyganiak <richard@cyganiak.de>, public-xg-rdb2rdf <public-xg-rdb2rdf@w3.org>
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 Tuesday, 2 February 2010 23:07:00 UTC