Problem 1:
Difference between 1st and 2nd Query is adding of function weight in the
projection.
>> SELECT ?fpredicate (count(distinct ?instance) AS ?ficount) (count(distinct
>> ?object) AS ?focount)
(fn:weights3(count(distinct ?instance), count(distinct ?object), 85620) AS
?coverage)
>>WHERE
>> { ?instance rdf:type movie:film .
>> ?instance ?fpredicate ?object
>> FILTER regex(str(?fpredicate), "http://data.linkedmdb.org/resource/";;,
>> "i")
>> }
>> GROUP BY ?fpredicate
In algebra. the additional part
>>(project (?fpredicate ?ficount ?focount ?coverage)
(extend ((?ficount ?.0) (?focount ?.1) (?coverage (<java:facet.weights3> ?.0
?.1 85620)))
>>(group (?fpredicate) ((?.0 (count distinct ?instance)) (?.1 (count distinct
>>?object)))
Problem 4:
First I have loaded my data using
tdbloader2 --loc /home/MyDatabases/LinkedMDB/ /home/Downloads/linkedmdb.nt
String directory = "/home/MyDatabases/LinkedMDB" ;
>>Dataset dataset = TDBFactory.createDataset(directory) ;
>>PrefixMapping premap =
>>dataset.asDatasetGraph().getDefaultGraph().getPrefixMapping();
System.out.println(premap.getNsPrefixMap().size());
is 0
Problem 5:
>>"StageGenerator"s are used by ARQ.
>>You can register your own - although TDB installs it's own query engine
>>factory and executor (OpExecutorTDB). StageGeneratorDirectTDB is only
>>used if a TDB-backed model is placed in a generate dataset, not one
>>obtained from TDBFactory.
I am sorry, I could not follow what
" if a TDB-backed model is placed in a generate dataset, not one
obtained from TDBFactory "
mean, Should not I extract dataset using TDBFactory ?
What should I do In order to make my Stategenerator in place of
StageGeneratorDirectTDB .. and also to get prefixes ?
Thank you
aj
