Ivan Mikhailov wrote:
Rob,
I've tried on my database (that is mix of dbpedia and few other
databases. Both queries return accurate results. So questions are:
1. What version of Virtuoso Open Source do you use?
5.0.6
2. What version of Virtuoso Open Source was used at the time you've
loaded the database?
It was 5.0.6 but I have had to recompile it after an upgrade from ubuntu
dapper to ubuntu hardy.
3. Did you create any additional indexes in RDF_QUAD table?
I followed this guide for creating additional indexes :
http://www.openlinksw.com/dataspace/kide...@openlinksw.com/weblog/kide...@openlinksw.com%27s%20BLOG%20%5B127%5D/1298
I have loaded data after I created this though, although I'd assume this
wouldn't be an issue. Other than that I haven't added any indexes.
4. What are the outputs of the following SQL commands:
explain ('sparql SELECT ?p ?o WHERE
{ <http://dbpedia.org/resource/Programmers> ?p ?o }');
Connected to OpenLink Virtuoso
Driver: 05.00.3028 OpenLink Virtuoso ODBC Driver
REPORT
VARCHAR
_______________________________________________________________________________
{
Precode:
0: $25 "org/resource/Programmers" := Call
DB.DBA.RDF_MAKE_IID_OF_QNAME_SAFE (<constant
(http://dbpedia.org/resource/Programmers)>)
7: BReturn 0
from DB.DBA.RDF_QUAD by RDF_QUAD_PSOG
Key RDF_QUAD_PSOG ASC ($28 "s-1-1-t0.P", $27 "s-1-1-t0.O")
row specs: <col=413 S = $25 "org/resource/Programmers">
Current of: <$30 "<DB.DBA.RDF_QUAD s-1-1-t0>" spec 5>
After code:
0: $31 "p" := Call id_to_iri ($28 "s-1-1-t0.P")
5: $32 "o" := Call __rdf_sqlval_of_obj ($27 "s-1-1-t0.O")
10: BReturn 0
Select ($31 "p", $32 "o", <$30 "<DB.DBA.RDF_QUAD s-1-1-t0>" spec 5>)
}
18 Rows. -- 2 msec.
explain ('sparql SELECT ?o WHERE
{ <http://dbpedia.org/resource/Programmers>
<http://dbpedia.org/property/redirect> ?o } ');
REPORT
VARCHAR
_______________________________________________________________________________
{
Precode:
0: $25 "org/resource/Programmers" := Call
DB.DBA.RDF_MAKE_IID_OF_QNAME_SAFE (<constant
(http://dbpedia.org/resource/Programmers)>)
7: $26 "org/property/redirect" := Call
DB.DBA.RDF_MAKE_IID_OF_QNAME_SAFE (<constant
(http://dbpedia.org/property/redirect)>)
14: BReturn 0
from DB.DBA.RDF_QUAD by RDF_QUAD_PSOG
Key RDF_QUAD_PSOG ASC ($28 "s-1-1-t0.O")
inlined <col=414 P = $26 "org/property/redirect"> , <col=413 S = $25
"org/resource/Programmers">
Current of: <$30 "<DB.DBA.RDF_QUAD s-1-1-t0>" spec 5>
After code:
0: $31 "o" := Call __rdf_sqlval_of_obj ($28 "s-1-1-t0.O")
5: BReturn 0
Select ($31 "o", <$30 "<DB.DBA.RDF_QUAD s-1-1-t0>" spec 5>)
}
17 Rows. -- 2 msec.
5. If index RDF_QUAD_OGPS is mentioned in the output of second explain()
but not in the output of the first explain(), then could you please
backup your database and try
I couldn't see RDF_QUAD_OGPS referenced in the above explain results.
Any other things I could try ?
Thanks
checkpoint;
drop index RDF_QUAD_OGPS;
create bitmap index RDF_QUAD_OGPS on DB.DBA.RDF_QUAD (O, G, P, S)
checkpoint;
then re-try that queries?
