Virtuoso performance

counts don't seem to be reliable

https://github.com/openlink/virtuoso-opensource/issues/112

https://github.com/openlink/virtuoso-opensource/issues/437

Action Item:
A new custom header is being added for this scenario (it will be live by
the time you read this mail), so as to provide additional information to
this situation. Basically, X-MaxRows: {ini-hard-limit-value}, which in
this case would be 10,000. Note the maximum is 2,000,000 for Virtuoso.

Graphs names

SELECT id_to_iri(REC_GRAPH_IID) FROM DB.DBA.RDF_EXPLICITLY_CREATED_GRAPH

ld_dir('/usr/local/virtuoso-opensource/var/lib/virtuoso/db', 'extraction_output.nt', 'http://ontosides/missing');

Execution

https://community.openlinksw.com/t/executing-commands-from-file-via-isql/1034/2

http://docs.openlinksw.com/virtuoso/rdfsparqlinline/

http://docs.openlinksw.com/virtuoso/rdfperfloading/

Profiling

https://community.openlinksw.com/t/isql-have-different-results-with-sparql-endpoint/1190/13

http://docs.openlinksw.com/virtuoso/opttechniques/

http://docs.openlinksw.com/virtuoso/rdfsparqlhashjoin/

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?

https://community.openlinksw.com/t/raid-10-vs-virtuoso-striping-what-is-the-best-for-io-performance/1407

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)');

http://docs.openlinksw.com/virtuoso/ptune/

Recommendations

CPU load goes up to 100% when Virtuoso runs its look up processing

https://github.com/openlink/virtuoso-opensource/issues/714

Virtuoso.ini param

http://docs.openlinksw.com/virtuoso/dbadm/

How to Update Large SPARQL Data avoiding due to database checkpoint abortion?

http://docs.openlinksw.com/virtuoso/howtoloadlargedatanocheckpointabort/

Translate and Analyze modes for analyzing sparql queries

http://docs.openlinksw.com/virtuoso/rdfperfcost/

The “MaxQueryCostEstimationTime"param should never be set in the INI file

https://sourceforge.net/p/virtuoso/mailman/message/36149213/

Compiling and configuring Virtuoso

https://github.com/dkmfbk/knowledgestore/wiki/Compiling-and-configuring-Virtuoso

Upgrading to the latest Virtuoso git develop/7 branch which is a 07.20.3219

https://github.com/openlink/virtuoso-opensource/issues/655

Returns statistics for a running server as a result set

status('rhck');

http://docs.openlinksw.com/virtuoso/fn_status/

Virtuoso 7 typically requires 10GB RAM per billion triples,

https://sourceforge.net/p/virtuoso/mailman/message/34566700/

What is the storage cost per triple?

http://docs.openlinksw.com/virtuoso/virtuosofaq1/

Virtuoso.ini settings parameters

http://docs.openlinksw.com/virtuoso/dbadm/#ini_Database

Performance diagnostics