; ; "Orri Erling" . , ; ; "Orri Erling's Blog" . ; . , , ; "Virtuoso 5.06 Updates" ; ; "Virtuoso 5.06 Updates" ; "2008-03-25T16:59:08Z"^^ ; "2008-03-26T11:58:58.000-04:00"^^ ; ; "15e8c09bf56ad567afcae2e808f0bd4e" ; ; "\n<p>I will here summarize the developments since the last <a href="http://data.openlinksw.com/oplweb/product_family/virtuoso#this" id="link-id15843368">Virtuoso</a> 5 Open Source release.</p> <p>On the <a href="http://dbpedia.org/resource/RDF" id="link-id101cae58">RDF</a> side, the bitmap intersection join has been improved quite a bit so that it is now almost always more than 2x more efficient than the equivalent nested loop join.</p> <p>XML trees in the object position in <a href="http://dbpedia.org/resource/RDF" id="link-id1172c108">RDF</a> quads were in some cases incorrectly indexed, leading to failure to retrieve quads.\u00C2\u00A0 This is fixed and should problems occur in existing databases, they can be corrected by simply dropping and re-creating an index.</p> <p>Also the cost model has been further tuned.\u00C2\u00A0 We have run the <a href="http://dbpedia.org/resource/TPC-H" id="link-idd65a998">TPC</a>-<a href="http://dbpedia.org/resource/TPC-H" id="link-id11a2bf48">H</a> queries with larger databases and have profiled it extensively.\u00C2\u00A0 There are improvements to locking, especially for concurrency of transactions with large shared lock sets, as is the case in the <a href="http://dbpedia.org/resource/TPC-H" id="link-id12cfd690">TPC</a>-<a href="http://dbpedia.org/resource/TPC-H" id="link-id15891ae0">H</a> queries.\u00C2\u00A0 The rules stipulate that these have to be run with repeatable read.\u00C2\u00A0 There are also optimizations for decimal floating point.</p> <p>A sampling of <a href="http://dbpedia.org/resource/TPC-H" id="link-id15b12eb0">TPC</a>-<a href="http://dbpedia.org/resource/TPC-H" id="link-id1172c740">H</a> queries translated into <a href="http://dbpedia.org/resource/SPARQL" id="link-id15533aa8">SPARQL</a> comes with the new demo database.\u00C2\u00A0 These show a live sample of the <a href="http://dbpedia.org/resource/TPC-H" id="link-id15b82cd8">TPC</a>-<a href="http://dbpedia.org/resource/TPC-H" id="link-id15521d50">H</a> schema translated into linked data, complete with <a href="http://dbpedia.org/resource/SPARQL" id="link-id15ae14d8">SPARQL</a> translations of the original queries.\u00C2\u00A0 Some work is still ongoing there but the relational to <a href="http://dbpedia.org/resource/RDF" id="link-id101b1240">RDF</a> mapping is mature enough for real business intelligence applications now.</p> <p>On the closed source side, we have some adjustments to the virtual database.\u00C2\u00A0 When using <a href="http://data.openlinksw.com/oplweb/product_family/virtuoso#this" id="link-id10888df0">Virtuoso</a> as a front end to Oracle, using the <a href="http://dbpedia.org/resource/TPC-H" id="link-id134a9378">TPC</a>-<a href="http://dbpedia.org/resource/TPC-H" id="link-id10366320">H</a> queries as a metric, the virtual database overhead is minimal.\u00C2\u00A0 Previously, we had some overhead because some queries were rewritten in a way that Oracle would not optimize as well as the original <a href="http://dbpedia.org/resource/TPC-H" id="link-id15536320">TPC</a>-<a href="http://dbpedia.org/resource/TPC-H" id="link-idfd4e278">H</a> text.\u00C2\u00A0 Specifically, turning an IN sub-query predicate into an equivalent EXISTS did not sit well with Oracle.</p>\n<a href="index.vspx?tag=database" rel="tag" style="display:none;">database</a><a href="index.vspx?tag=databases" rel="tag" style="display:none;">databases</a><a href="index.vspx?tag=semanticweb" rel="tag" style="display:none;">semanticweb</a><a href="index.vspx?tag=sparql" rel="tag" style="display:none;">sparql</a><a href="index.vspx?tag=lubm" rel="tag" style="display:none;">lubm</a><a href="index.vspx?tag=benchmarking" rel="tag" style="display:none;">benchmarking</a>" ; "Virtuoso 5.06 Updates" ; ; ; , , , ; ; ; "2008-03-25T16:59:08Z" ; "2008-03-26T15:58:58Z" ; ; "http://www.openlinksw.com/dataspace/oerling/weblog/Orri%20Erling%27s%20Blog/1326" ; "alternate" . ; ; "Orri Erling" ; . , ; ; "Orri Erling's Blog" ; ; ; . ; ; . ; .