On SPARQL queries with FILTER ( ?date < "..."^^xsd:dateTime )

[Paolo Castagna]

Hi,
a query pattern I often see is filtering by some xsd:dateTime interval, for
example:

PREFIX xsd: <http://www.w3.org/2001/XMLSchema#>
SELECT * {
    ?s <http://purl.org/dc/elements/1.1/date> ?date .
    FILTER ( ( ?date > "2011-03-03T00:00:00Z"^^xsd:dateTime ) &&
             ( ?date < "2011-06-06T00:00:00Z"^^xsd:dateTime ) )
}

Even with moderate size stores this query can take quite a while to execute.
I'd like to know if there is something I could do to speedup these kind of
queries.

I understand that the xsd:dateTime value is encoded by the NodeTableInline.
However, I am not sure this is exploited at query time or I'd llike to
understand if there is something we could do better to further improve
performances of queries similar to the one above.

Thanks,
Paolo