Matthias Samwald wrote:
Dear all,
I am facing a relatively simple problem, but it seems like there is no
mechanism to really address this issue: I have a large RDF database
(>400 million triples, dozens of named graphs) in a Virtuoso 5 instance
that I want to transfer to a Virtuoso 6 instance. What is the best way
of doing that? The main problem is re-creating the named graphs.
Virtuoso still has no mechanism to dump RDF data including graph
provenance (correct?),
You can write a simple enough stored procedure to do that.
-- Dump a graph to specified filename in DAV
create procedure me..dumpgraph (in iri varchar, in fname varchar)
{
declare res, spq, state, msg, maxrows, metas, rset, ses, triples, s,
path any;
spq:=sprintf('sparql CONSTRUCT { ?s ?p ?o . } from <%s> WHERE { ?s ?p ?o
. }',iri);
-- first dump to TTL files
dbg_printf('Preparing query..\n');
ses:=string_output();
exec (spq, state, msg, vector(), maxrows, metas, rset);
path:=sprintf('/DAV/home/me/dumps/%s.ttl', fname);
dbg_printf('Path is: [%s]', path);
triples := rset[0][0];
rset := dict_list_keys (triples, 1);
DB.DBA.RDF_TRIPLES_TO_TTL (rset, ses);
s := string_output_string (ses);
DAV_RES_UPLOAD (path, s, 'application/rdf+xml', '110100100NM', 'me',
null, 'me', 'me');
-- Then dump to RDF/XML files
dbg_printf('Preparing query..\n');
ses:=string_output();
exec (spq, state, msg, vector(), maxrows, metas, rset);
path:=sprintf('/DAV/home/me/dumps/%s.rdf', fname);
dbg_printf('Path is: [%s]', path);
triples := rset[0][0];
rset := dict_list_keys (triples, 1);
DB.DBA.RDF_TRIPLES_TO_RDF_XML_TEXT (rset, 1, ses);
s := string_output_string (ses);
DAV_RES_UPLOAD (path, s, 'application/rdf+xml', '110100100NM', 'me',
null, 'me', 'mypassword');
-- Log the graph IRI/fname mapping
spq:=sprintf('sparql PREFIX rdfs:
<http://www.w3.org/2000/01/rdf-schema#>\ninsert into graph
<http://localhost:8892/dumps/> { <%s> <rdfs:isDefinedBy>
<http://localhost:8892/dumps/%s.rdf> }', iri, fname);
dbg_printf('Updating quadstore with [%s]\n', spq);
exec (spq, state, msg, vector(), maxrows, metas, rset);
};
Obviously you don't have to choose DAV output if you don't want, just as
long as the filesystem dir is listed in DirsAllowed in the ini-file.
HTH,
~Tim
--
Tim Haynes
Product Development Consultant
OpenLink Software
<http://www.openlinksw.com/>
