LDCache tips

[Joshua Dunham <jo...@vrtx.com>]

Hi Marmotta Users,

Could someone clue me in on how to use the LDCache module for the following example?

We analyze data which yields an ID that is the same as an ID on a remote linked data site. Let’s say it’s Q6GZX4 and the remote endpoint would be http://www.unprot.org/uniprot/Q6GZX4 . What I would like is that when we add a new ID of this type to our local marmotta, that the LDCache will pull the record from the remote site’s RDF data http://www.unprot.org/uniprot/Q6GZX4.rdf .

if you have tips on the best way to write the relationship into the store and a MWE sparql query that could show some data from it that would be awesome!

-Joshua


Joshua Dunham
Scientific Computing | Vertex
E: joshua_dunham@vrtx.com
P: 617-229-5157
W: http://www.vrtx.com
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S: joshua.dunham

This email message and any attachments are confidential and intended for use by the addressee(s) only. If you are not the intended recipient, please notify me immediately by replying to this message, and destroy all copies of this message and any attachments. Thank you.

Re: LDCache tips

[Sergio Fernández <wi...@apache.org>]

Hi Joshua,

not sure if I  understood you correctly, but I think you are asking two
questions:

First, how to resolve URI as http://www.unprot.org/uniprot/Q6GZX4 to data
served at http://www.unprot.org/uniprot/Q6GZX4.rdf? The regexuri LDCache
endpoint was introduced exactly for those cases where servers are not fully
Linked Data friendly.

The second is how to trigger the caching of those references resources? In
the Marmotta KiWi stack LDCache is triggered every time a triple-pattern
like "<uri> ?p ?o" is requested from the triple store. Then LDCache tries
to load URI from remote according the available configuration.

That remains completely valid for raw Linked Data requests, LDP requests
and LDPath queries, but not anymore for SPARQL. Because performance reasons
the new SPARQL implementation by-passes the Sesame stack, so queries are
directly issued to the database. That means that if you want to used the
cached data for SPARQL queries it'd need to be cached before.

A trick we commonly use is to force the cache triggering by sending a
simple LDPath program that matches with the resources you want to cache
eagerly. In you case, whatever statement you use lo link with those IDs.

If our users community remains asking about such eager population, we might
need to think about an infrastructure to directly support it.

Hope that helps.

Cheers,

On Fri, Apr 10, 2015 at 11:19 PM, Joshua Dunham <jo...@vrtx.com>
wrote:

> Hi Marmotta Users,
>
> Could someone clue me in on how to use the LDCache module for the
> following example?
>
> We analyze data which yields an ID that is the same as an ID on a remote
> linked data site. Let’s say it’s Q6GZX4 and the remote endpoint would be
> http://www.unprot.org/uniprot/Q6GZX4 . What I would like is that when we
> add a new ID of this type to our local marmotta, that the LDCache will pull
> the record from the remote site’s RDF data
> http://www.unprot.org/uniprot/Q6GZX4.rdf .
>
> if you have tips on the best way to write the relationship into the store
> and a MWE sparql query that could show some data from it that would be
> awesome!
>
> -Joshua
>
>
> Joshua Dunham
> Scientific Computing | Vertex
> E: joshua_dunham@vrtx.com
> P: 617-229-5157
> W: http://www.vrtx.com
> L: http://linkedin.com/in/joshuadunham
> S: joshua.dunham
>
> This email message and any attachments are confidential and intended for
> use by the addressee(s) only. If you are not the intended recipient, please
> notify me immediately by replying to this message, and destroy all copies
> of this message and any attachments. Thank you.
>



-- 
Sergio Fernández
Partner Technology Manager
Redlink GmbH
m: +43 6602747925
e: sergio.fernandez@redlink.co
w: http://redlink.co