[Neo] VerboseQuadStore and spaql

Mattias Persson mattias at neotechnology.com
Fri Jan 30 17:31:02 CET 2009


Hi Lyudmila,

as Emil pointed out our sparql support doesn't yet support all
possible cases, but according to my knowledge a ?S P ?O construct is
supported and tests in the sparql engine verifies that. It can however
depend on what other triple constraints your query has. The neo sparql
engine needs (as of now, at least) some kind of reasonable starting
point; somewhere to start the traversing from and it may be that
decision which is causing your problems. If you could send your sparql
query I could make a much better conclusion as to the source of the
problem.

Best,

Mattias

2009/1/30 Emil Eifrem <emil at neotechnology.com>:
> On Thu, Jan 29, 2009 at 9:54 PM, Lyudmila Balakireva <ludab at lanl.gov> wrote:
>> Hello,
>> I was testing sail rdf  component  and  I  made test store based
>> on    VerboseQuadStore .
>> I have problem with predicate  in sparql .  If I  specify  predicate
>> like  ?x dc:type ?z  the query does not returning anything. (I do
>> have  dc namespace prefix). It is work if I do (?x?y?z) or (?x ?y
>> "snow")  or url in subject or object position.
>> It is work with specific predicate if I do getStatements().
>> Any clue would be great.
>
> Hi Luda,
>
> Our Sparql support is so-so: it's optimized *enough* for the
> particular commercial use cases that our Sparql-swinging customers
> have required so far. And the ?s predicate ?o pattern may very well be
> one that hasn't been required (yet). But Mattias would know more about
> this than me. Mattias?
>
> It's weird though that it works in getStatements(). How have you
> configured and assembled your components? Also, do you use
> Sparql-over-SAIL or the Neo4j Sparql engine?
>
> Cheers,
>
> --
> Emil Eifrém, CEO [emil at neotechnology.com]
> Neo Technology, www.neotechnology.com
> Cell: +46 733 462 271 | US: 206 403 8808
> _______________________________________________
> Neo mailing list
> User at lists.neo4j.org
> https://lists.neo4j.org/mailman/listinfo/user
>



-- 
Mattias Persson, [mattias at neotechnology.com]
Neo Technology, www.neotechnology.com


More information about the User mailing list