We have a new demo online at http://demo.openlinksw.com/tpc-h. This takes the industry standard TPC-H benchmark data and presents it as linked data with a SPARQL end point and dereferenceable URIs.
This is an example of using Virtuoso's relational-to-RDF mapping for publishing business data, for browsing using the linked data principles and opening it to analytics queries in SPARQL.
As noted before, we have extended SPARQL with aggregation and nested queries, thus making it a viable SQL substitute for decision support queries.
The article at http://virtuoso.openlinksw.com/dataspace/dav/wiki/Main/VOSTPCHLinkedData gives details and the source code for the implementation.
We are still working on some aspects of the more complex TPC-H queries, thus the demo is not complete with all the 22 queries. This is however enough to see a representative sample of how analytics queries work with SPARQL and Virtuoso's SQL-to-RDF mapping. The demo will be part of the next Virtuoso Open Source download, probably out next week.