I have this kind of queries that do not perform as expected (transaction
timeout usually).
Here an example on dbpedia:
CONSTRUCT { <http://dbpedia.org/resource/Coen_brothers> ?p ?o.
?sub ?p_sub ?o_sub.
?type ?p_type ?o_type.
}
where {
<http://dbpedia.org/resource/Coen_brothers> ?p ?o
OPTIONAL {
<http://dbpedia.org/resource/Coen_brothers>
<http://www.w3.org/1999/02/22-rdf-syntax-ns#type> ?type.
?type ?p_type ?o_type.
}
OPTIONAL {
<http://dbpedia.org/resource/Coen_brothers>
<http://purl.org/dc/terms/subject> ?sub.
?sub ?p_sub ?o_sub.
}
}
The query answer very fast if I remove one of the optional or the "?p
?o" part.
Is it something expected?
Can you suggest me another query to get the same response?
Would use all the properties in separated optional works faster?
Thanks
Nicola
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