Hi Kingsley,
thanks for your reply. We are not working on the DBPedia dataset, but
are currently evaluating different models for metadata storage with a
constructed set of test data. We are only using some of the DBPedia
concepts and properties.
However, I could try to adapt the query to DBPedia and give it a try.
Cheers
Martin
Am 22.04.2010 15:26, schrieb Kingsley Idehen:
> Mitko Iliev wrote:
>> Hi Martin,
>>
>> The default indexes should do, i don't see wrong plan or similar. So it's
>> better to send us the execution plan so we can see how this query compiles
>> on your site; to do this put the query in explain ('sparql ...query here
>> ..') and execute via command line ISQL tool.
>> When doing explain note that query should begin with SPARQL keyword.
>> Also what are INI settings in Parameters section specifically
>> NumberOfBuffers, how large is working set? Check the staistics with status
>> () command again with ISQL tool.
>>
>
> In addition, if this is all DBpedia dataset oriented you can simply test
> for performance disparity (relative to your instance) across:
>
> 1. http://dbpedia.org/sparql
> 2. http://lod.openlinksw.com/sparql -- this has 8.5 Billion+ Triples.
>
> Then we can complete analysis of your query using our existing live
> instances.
>
> Kingsley
>> Best Regards,
>> Mitko
>>
>> On Apr 22, 2010, at 12:45 PM, Martin Gerlach wrote:
>>
>>
>>> Hi,
>>>
>>> The following SPARQL Query returns approx. 10000 results out of 35
>>> million triples.
>>>
>>> select [distinct] ?conflict ?metadata [from
>>> <http://example.com/mygraph>] where {
>>> ?conflict a <http://dbpedia.org/ontology/MilitaryConflict> .
>>> ?conflict ?p <http://dbpedia.org/ontology/Event> .
>>> ?p rdfs:subPropertyOf rdf:type .
>>> ?p <http://example.com/mymetadata> ?metadata .
>>> }
>>>
>>> There are only 4 graphs including the Virtuoso default graphs and all
>>> triples concerned are in <http://example.com/mygraph>. RDF_QUAD has the
>>> following default indexes: GS, OP, POGS, SP.
>>>
>>> Now the given query seems to be really slow. With FROM clause it is even
>>> slower than without. Using DISTINCT or not does not seem to have much
>>> impact.
>>>
>>> Which indexes could help? I would think the query triple "?conflict ?p
>>> <Event>" could be the cause for the delay - shouldn't an index on just
>>> "O", "O,S", or "G,O,S" help? I tried each of the three without much of
>>> an effect.
>>> Are there other tables which need to be indexed in order to increase
>>> SPARQL perfomance?
>>>
>>> (Background: We have subclassed rdf:type dynamically for each ?s a
>>> <Event> triple in order to annotate metadata, e.g. provenance, source,
>>> time, ...)
>>>
>>> Any ideas?
>>>
>>> Thanks and cheers,
>>> Martin
>>>
>>>
>>> --
>>> ------------------------------------------------------------------------
>>> Martin Gerlach
>>> Research
>>>
>>> Neofonie
>>> Technologieentwicklung und
>>> Informationsmanagement GmbH
>>> Robert-Koch-Platz 4
>>> 10115 Berlin
>>> fon: +49.30 24627 413
>>> fax: +49.30 24627 120
>>> martin.gerl...@neofonie.de <mailto:martin.gerl...@neofonie.de>
>>> http://www.neofonie.de
>>>
>>> Handelsregister
>>> Berlin-Charlottenburg: HRB 67460
>>>
>>> Geschaeftsfuehrung
>>> Helmut Hoffer von Ankershoffen
>>> (Sprecher der Geschaeftsfuehrung)
>>> Nurhan Yildirim
>>>
>>> ------------------------------------------------------------------------
>>>
>>> Das WePad ist ein Tablet der neuesten Generation. Dem Nutzer bietet es
>>> schnellen Zugang zum Internet, eine komplette Welt von sofort nutzbaren
>>> Applikationen und einfachen Zugriff auf Bücher, Fotos sowie auf Magazine
>>> und Tageszeitungen verschiedener Verlage, die mit dem WeMagazine
>>> ePublishing Eco System realisiert wurden. Mehr über das WePad auf
>>> www.wepad.mobi <http://www.wepad.mobi> oder auf www.facebook.com/WePad
>>> <http://www.facebook.com/WePad>.
>>>
>>>
>>> ------------------------------------------------------------------------------
>>> _______________________________________________
>>> Virtuoso-users mailing list
>>> Virtuoso-users@lists.sourceforge.net
>>> https://lists.sourceforge.net/lists/listinfo/virtuoso-users
>>>
>>
>>
>> --
>> Mitko Iliev
>> Developer Virtuoso Team
>> OpenLink Software
>> http://www.openlinksw.com/virtuoso
>> Cross Platform Web Services Middleware
>>
>>
>> ------------------------------------------------------------------------------
>> _______________________________________________
>> Virtuoso-users mailing list
>> Virtuoso-users@lists.sourceforge.net
>> https://lists.sourceforge.net/lists/listinfo/virtuoso-users
>>
>>
>
>
--
------------------------------------------------------------------------
Martin Gerlach
Research
Neofonie
Technologieentwicklung und
Informationsmanagement GmbH
Robert-Koch-Platz 4
10115 Berlin
fon: +49.30 24627 413
fax: +49.30 24627 120
martin.gerl...@neofonie.de <mailto:martin.gerl...@neofonie.de>
http://www.neofonie.de
Handelsregister
Berlin-Charlottenburg: HRB 67460
Geschaeftsfuehrung
Helmut Hoffer von Ankershoffen
(Sprecher der Geschaeftsfuehrung)
Nurhan Yildirim
------------------------------------------------------------------------
Das WePad ist ein Tablet der neuesten Generation. Dem Nutzer bietet es
schnellen Zugang zum Internet, eine komplette Welt von sofort nutzbaren
Applikationen und einfachen Zugriff auf Bücher, Fotos sowie auf Magazine
und Tageszeitungen verschiedener Verlage, die mit dem WeMagazine
ePublishing Eco System realisiert wurden. Mehr über das WePad auf
www.wepad.mobi <http://www.wepad.mobi> oder auf www.facebook.com/WePad
<http://www.facebook.com/WePad>.
