Profiling
http://vos.openlinksw.com/owiki/wiki/VOS/VOSBitmapIndexing
http://vos.openlinksw.com/owiki/wiki/VOS/VirtFixBrokenQuadStoreIndex
http://vos.openlinksw.com/owiki/wiki/VOS/VirtRDFPerformanceTuning
http://docs.openlinksw.com/virtuoso/ptune/
http://docs.openlinksw.com/virtuoso/perfdiag/
http://docs.openlinksw.com/virtuoso/fn_prof_enable/
http://vos.openlinksw.com/owiki/wiki/VOS/VirtSPARQLPrefOrder
output:format
Answered on the Virtuoso Users mailing list where the question was also asked...
Dumping results in various formats can be done by using the
define output:format "{XX}"
pragma, so in your case it would be:
SQL> sparql define output:format "TURTLE" CONSTRUCT ...
Other possible formats are:
NICE_TTL
RDF_XML
etc.
When using the ISQL client to fetch long texts, use the set blobs on; directive to avoid receiving a data truncated warning.
i.e.:
SQL> set blobs on;
SQL> sparql define output:format ...
For CONSTRUCT, the supported formats are:
TRIG, TTL, JSON, JSON;TALIS, SOAP, RDF/XML, NT, RDFA;XHTML, JSON;RES, HTML;MICRODATA, HTML, JS, ATOM;XML, JSON;ODATA, XML, CXML;QRCODE, CXML, HTML;UL, HTML;TR, JSON;LD, CSV, TSV, NICE_TTL, HTML;NICE_MICRODATA, HTML;SCRIPT_LD_JSON, HTML;SCRIPT_TTL, HTML;NICE_TTL
iSQL
isql 1111 errors=stdout <test.sql >test.out
isql 1111 dba dba VERBOSE=OFF 'EXEC=status()' test.sql test2.sql -i arg1 arg2
http://docs.openlinksw.com/virtuoso/isqlgentesttool/ http://docs.openlinksw.com/virtuoso/invokingisql/
SPARQL query limiting results to 100000 triples
https://community.openlinksw.com/t/sparql-query-limiting-results-to-100000-triples/2131
Prevent Limits of Sorted LIMIT/OFFSET query
SELECT ?p ?s
WHERE
{
{
SELECT DISTINCT ?p ?s
FROM <http://dbpedia.org>
WHERE
{
?s ?p <http://dbpedia.org/resource/Germany>
} ORDER BY ASC(?p)
}
}
OFFSET 50000
LIMIT 1000
http://docs.openlinksw.com/virtuoso/rdfsparqlimplementationextent/
RAID 10 vs Virtuoso striping. What is the best for IO performance?
Backward chaining
https://sourceforge.net/p/virtuoso/mailman/message/34144456/
Stripping
https://sourceforge.net/p/virtuoso/mailman/virtuoso-users/?viewmonth=201003
Efficient Use of SQL - SQL Execution profiling
profile ('SELECT COUNT (*) from ct_c a, ct_c b WHERE a.k2 = b.k1 option (loop, order)');
Recommendations
CPU load goes up to 100% when Virtuoso runs its look up processing
Virtuoso.ini param
How to Update Large SPARQL Data avoiding due to database checkpoint abortion?
Translate and Analyze modes for analyzing sparql queries
The “MaxQueryCostEstimationTime"param should never be set in the INI file
Compiling and configuring Virtuoso
Upgrading to the latest Virtuoso git develop/7 branch which is a 07.20.3219
Returns statistics for a running server as a result set
status('rhck');
Virtuoso 7 typically requires 10GB RAM per billion triples,
What is the storage cost per triple?
Virtuoso.ini settings parameters
Performance diagnostics
http://docs.openlinksw.com/virtuoso/perfdiag/