Hello,

mo wrote:
> Hi,
> 
> I tried it, but
> 
> define input:inference
> 'http://dbpedia.org/resource/inference/rules/yago#'
> 
> PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
> PREFIX dbp: <http://dbpedia.org/property/>
> PREFIX yago: <http://dbpedia.org/class/yago/>
> 
> SELECT        count(distinct(?project)) as ?num
> 
> WHERE {
>       ?project rdf:type yago:Building102913152.
> }
> 
> gives me only 2959 results on http://dbpedia.org/sparql
> (887 without the inferencing snippet)
> 
> What am I doing wrong?

I tried to figure out what the problem might be, but I'm quite busy at
the moment. The low number is a result of the new YAGO data sets in
DBpedia 3.1., but I'm unsure why the number of buildings is so lower (I
expected it to rise). One problem are remaining encoding issues in the
YAGO DBpedia export, but this probably only marginally influences this
number. What you could try is to visit the YAGO website [1] and try to
find out whether the number of buildings in YAGO itself is higher than
in DBpedia. Let us know if you get any insights. Note that YAGO uses
different identifiers, e.g.:

<http://mpii.de/yago/resource/St._Peter's_Basilica>
<http://www.w3.org/2002/07/owl#sameAs>
<http://dbpedia.org/resource/St._Peter's_Basilica> .

> (Oddly, if I replace rdf:type with a variable, I get even less.)      

That may be due to the fact that RDFS inferencing in Virtuoso is only
done if rdf:type is explicitly given in the query.

Kind regards,

Jens

[1] http://www.mpi-inf.mpg.de/~suchanek/downloads/yago/

-- 
Dipl. Inf. Jens Lehmann
Department of Computer Science, University of Leipzig
Homepage: http://www.jens-lehmann.org
GPG Key: http://jens-lehmann.org/jens_lehmann.asc

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