Re: Restpark - Minimal RESTful API for querying RDF triples

On 4/16/13 5:22 PM, Aidan Hogan wrote:
> On 16/04/2013 22:05, Kingsley Idehen wrote:
>> On 4/16/13 4:15 PM, Aidan Hogan wrote:
>>>
>>> The ability to answer "I don't know" or "cannot compute right now" or
>>> "I need more time" would make anything trivially scalable. But "I
>>> don't know" or "cannot compute" or "I need more time" is not a valid
>>> SPARQL answer. Nor is stopping after the first X answers are returned.
>> Let's have a constructive conversation via SPARQL protocol URLs.
>
> I thought my comments were constructive? (If not, I'd be happy to hear 
> why not.)
>
> Anyways, as per my previous reply ...
>
> With respect to this SPARQL query service:
>
>     http://lod.openlinksw.com/sparql
>
> I would like a response complaint with the SPARQL standard for either 
> of the following two SPARQL queries:
>
>     SELECT * WHERE
>     {?s foaf:knows ?o}
>
> or
>
>     SELECT * WHERE
>     {?s foaf:knows ?o . ?o foaf:knows ?o2 .}
>
> Cheers,
> Aidan
>
>
>
Did you perform a count on either? If so, why no LIMIT in the query ?  
If you want no LIMIT into what bucket are you placing the result? Would 
you dare send the following to a decently sized RDBMS and use it as the 
basis for assessing scale:

SELECT * FROM TABLE_X

Anyway, re. my comments above,  SPARQL Protocol URLs:

1. http://lod.openlinksw.com/c/GNC4S3R -- query result re. count
2. http://lod.openlinksw.com/c/GSNV76O -- query definition re. the above.

So what do you do when the result set exceeds the capacity of the 
bucket? You make a scrollable cursor (the types vary: snapshot, keyset, 
dynamic, or mixed model) and then page through the data. Alternatively, 
you make a multi-dimensional view (known as facets in the RDF / Semantic 
Web UI world) and you leverage the entity relationship semantics as the 
basis for a scrollable cursor.

The paragraph above describes what's happening at: 
http://lod.openinksw.com/fct -- its a scrollable cursor engine, 
something that's quite common in the RDBMS realm, but they lack relation 
semantics of RDF. Same thing applies to column-storage, key compression, 
and vectorized execution which are also reapplications of RDBMS realm 
technology in new RDF context so that we have the best of both worlds.



-- 

Regards,

Kingsley Idehen	
Founder & CEO
OpenLink Software
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