Re: AW: Discovering QB observations (Was: Re: ORG browser)

On 12/07/2013 04:49 PM, Benedikt Kaempgen wrote:
> Hello,
>
> Thanks for your thoughts.
>
>> Tell me if I’m wrong, but I’m not aware of any use of QB that relies on the kind of dataset-to-(slice-to-)observation navigation that you describe.
>
> Since in the Linked Data Cubes Explorer [1] we rely on resolveable URIs, I am looking for recommendations of how to fetch all relevant content for a qb:DataSet.
>
>  From the discussions, I see the following possibilities that the application should try:
>
> * Resolving the dataset URI also returns blank nodes of observations including their outgoing links such as to the dataset or dimension values.
> * Resolving the dataset URI returns incoming links from observation URIs that can be resolved, separately, to retrieve their outgoing links.
> * Resolving the dataset URI returns outgoing links to slices, that in turn link to either blank nodes of observations with their outgoing links or to observation URIs that can be resolved for their outgoing links.
> * Resolving the dataset URI returns outgoing links void:sparqlEndpoint or void:dataDump that lead to RDF representations of all observations.
>
>> If you mean there is no link from a qb:DataSet to each of its own
> qb:Observations, that's true. But, there are slices in some 270.info
> datasets. Can you clarify? Is there a particular dataset you are looking
> at or are you only referring to the Linked SDMX implementation? Would
> you mind creating an issue https://github.com/csarven/linked-sdmx if
> there is a fundamental problem with the transformation? Much appreciated!
>
> Thanks, Sarven. If your datasets provide one of the above possibilities to reach the observations via lookups that is great.
>
> Not related to observations but metadata: If I only want to crawl the metadata of your datasets, however, I see a problem with blank nodes.
>
> For instance, dataset http://oecd.270a.info/dataset/HEALTH_STAT links to its structure http://oecd.270a.info/structure/HEALTH_STAT that however only links to blank nodes of components but does not return their outgoing links. Can you tell me how I would find such outgoing links?

> Best,
>
> Benedikt
>
> [1] <http://www.ldcx.linked-data-cubes.org:8000/ldcx-trunk/ldcx/ld-cubes-explorer.html>

You are right about the metadata. This is my bad. It should move away 
from blank nodes. Historically it is due to following along the 
convention that is used in the QB spec examples.

So, unfortunately, you have to use SPARQL to get to them at the moment. 
I've created an issue:

https://github.com/csarven/linked-sdmx/issues/35

will resolve and republish for *.270a.info

I think that might just be the last group of blank nodes. Minus the 
LODStats stuff..

Thanks.

-Sarven

Received on Saturday, 7 December 2013 17:03:43 UTC