Sebastian Hellmann wrote:
Hello,
if I use a
SELECT DISTINCT ?s
{?s ?p ?o.
?o bif:contains "Aspirin".
}
and activate owl:sameAs reasoning, will it have any effect?
Naturally.
When you enable owl:sameAs context rule you are asking Virtuoso to
produce an union expansion across all entities in the owl:sameAs relation.
To see this whole thing in effect simply take a look at the "Micheal
Jackson" example [1] that I've banded around for a few months now. Note,
what happens when you click on the Identifiers in the "Direct" and
"Indirect" Co-reference tabs while the "owl:sameAs" context rule is
disabled, then repeat the actions when its enabled (via Settings tab)
ditto when the "b3sifp" context rule is enabled (which makes an even
larger union expansion based on fuzzy rule that designated "foaf:name"
as an Inverse Functional Property".
We want to query for all subjects associated to a certain label, i.e.
bif:contains '"Aspirin"' on the LODD data.
The problem is, that they contain 7 datasets about drugs and therefore a
lot of duplicates, partly linked with owl:sameAs across the 7 graphs.
So if we make a distinct query for 'Aspirin', will we get a unified set
of subjects or all?
You will have a set of subject identifiers that all lead you to the same
solution comprised of:
1. DISTINCT filter
2. All properties and values across entities in the relation.
You can basically substitute "Michael Jackson" for Aspirin and repeat my
example at: http://lod.openlinksw.com/fct .
Links:
1.
http://lod.openlinksw.com/fct/rdfdesc/usage.vsp?g=http%3A%2F%2Fdbpedia.org%2Fresource%2FMichael%5FJackson&tp=3
2.
http://www.semanticoverflow.com/questions/217/how-is-inference-used-in-practice
Kingsley
Regards,
Sebastian
--
Regards,
Kingsley Idehen Weblog: http://www.openlinksw.com/blog/~kidehen
President & CEO
OpenLink Software Web: http://www.openlinksw.com
