good afternoon;

> On 2017-05-07, at 10:55, Laura Morales <[email protected]> wrote:
> 
>> i do not understand the approach to be one which deploys a local sparql 
>> _endpoint_.
>> the posted software (http://linkeddatafragments.org/software/) embeds the 
>> sparql processor in the application.
>> whether the application turns around and acts as a sparql endpoint is a 
>> separate question.
> 
> 
> oh, I didn't expect this. From my understanding, LDF servers are supposed to 
> return only simple subsets of their data, for example all values for a single 
> subject "<subject> ?p ?o". So, for more complex queries I don't see how it's 
> possible to answer the query without downloading huge chunks of the data and 
> build some local graph.

that is what the client-side sparql processor does.
their papers go through the numbers and, as the saying goes, they’re also just 
cooking with water[1].
it's just that they have to carry theirs a bit further from the spring.

> 
> 
>> [..] one means which they introduce to govern server resource usage is 
>> response paging, which is also available from a sparql endpoint.
> 
> 
> How do I activate this on Jena/Fuseki? Sounds useful to avoid returning too 
> much data at once.

the language itself is limited in that limit/offset slices[2] are required to 
be in terms of constant values and it is unfortunate, that the sparql protocol 
does not standardize a way to carry those constraints in a request.

various implementations provide extensions for that.
- - -
[1] : https://en.wiktionary.org/wiki/auch_nur_mit_Wasser_kochen
[2] : https://www.w3.org/TR/2013/REC-sparql11-query-20130321/#solutionModifiers
---
james anderson | [email protected] | http://dydra.com





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