- From: Ivan Mikhailov <imikhailov@openlinksw.com>
- Date: Fri, 12 Mar 2010 23:30:12 +0600
- To: Lee Feigenbaum <lee@thefigtrees.net>
- Cc: RDB2RDF Working Group <public-rdb2rdf-wg@w3.org>
Hello Lee, > > CONSTRUCT approach does not provide enough information about mapping to > > SPARQL-to-SQL optimizing compiler. Efficient mapping requires much more > > details than CONSTRUCT may fit. It would be nice to use CONSTRUCT but > > we've made much more complicated language to not kill the performance. > > Can you talk more about the requirements that you've identified for a > mapping language for performance reasons that go beyond the expressivity > of CONSTRUCT queries? Is there a write-up of this somewhere? I've re-checked docs I have for a feature but found no complete list, like one rationale+example pair per feature. http://docs.openlinksw.com/virtuoso/rdfsparqlintegrationmiddleware.html#rdfviews contains description of our mapping language with some (boring) examples and http://esw.w3.org/topic/Rdb2RdfXG/ReqForMappingByOErling presented to the group before contains mapping requirements backed by the experience accumulated by developers of Virtuoso-based applications. I'll try to prepare some list of cases in form of --- a SPARQL query, --- a "good" mapping with a feature in question, --- resulting SQL (good one), --- a bad SQL if the feature is missing. The problem is to find queries that will result in readable SQLs. Best Regards, Ivan Mikhailov OpenLink Software http://virtuoso.openlinksw.com
Received on Friday, 12 March 2010 17:30:46 UTC