---+Set Standard Prefix Names for common vocabularies

In order to set  standard prefix names for common vocabularies on dumps to either .n3 or .ttl, you should use the <code>[[http://docs.openlinksw.com/virtuoso/fn_xml_set_ns_decl.html][xml_set_ns_decl]]</code> Virtuoso function.

The initial list of namespace declarations can be found by executing from iSQL or Conductor UI:
<verbatim>
SQL> SELECT * FROM DB.DBA.SYS_XML_PERSISTENT_NS_DECL;
</verbatim>


---++Example

   1. Load the ontology, for ex.:
<verbatim>
SQL> DB.DBA.RDF_LOAD_RDFXML (http_get('http://lod.taxonconcept.org/ontology/txn.owl'), '', 'http://lod.taxonconcept.org/ontology/txn.owl#');

Done. -- 109 msec.
</verbatim>
   1 Check total triples retrieved:
<verbatim>
SQL>SPARQL 
SELECT COUNT(*)  
from <http://lod.taxonconcept.org/ontology/txn.owl#>
WHERE {?s ?p ?o};
callret-0
INTEGER
_______________________________________________________________________________

495

1 Rows. -- 16 msec.
</verbatim>
   1 Register the XML NS prefix:
<verbatim>
SQL>DB.DBA.XML_SET_NS_DECL ('txn', 'http://lod.taxonconcept.org/ontology/txn.owl#', 2);
Done. -- 0 msec.
</verbatim>
   1 Use the prefix, for ex. executing:
<verbatim>
SQL>SPARQL 
SELECT COUNT(*) 
WHERE
   {
     ?s ?p txn:SpeciesConcept
    };

callret-0
INTEGER
_______________________________________________________________________________

25

1 Rows. -- 0 msec.
</verbatim>