Re: Linked Data Fragments: Web-scale querying

Hi all,

An interesting discussion!!!. A good overview and a fine-grained
experimental evaluation of SPARQL query federation approaches presented in
[1] might be of  interest.

[1] http://www.semantic-web-journal.net/system/files/swj625.pdf.


Best,
Muhammad Saleem
PhD student AKSW, University of Leipzig, Germany
URL: https://sites.google.com/site/saleemsweb/
Skype: saleem.muhammd


On Wed, Mar 19, 2014 at 3:03 PM, Olaf Hartig <ohartig@uwaterloo.ca> wrote:

> Hi Martynas,
>
> On Wednesday 19 March 2014 12:58:15 Martynas Jusevičius wrote:
> > Ruben,
> >
> > interesting stuff. I remember another project that does something like
> that:
> > SQUIN http://squin.sourceforge.net/index.shtml
>
> SQUIN implements a traversal-based query execution strategy that relies
> only
> on the Linked Data publishing principles (i.e., the possibility to look up
> HTTP URIs). Query processing approaches that have this property are
> typically
> referred to as Linked Data query processing. If you want to get an
> overview on
> these approaches, you may want to check out my recent survey [1].
>
>
> > How does LDF compare to to it?
>
> I understand LDF more as an alternative practice for publishing (Linked)
> data
> on the Web. However, the primary purpose for proposing this practice (as
> Ruben
> and his colleagues emphasize in their LDOW paper) his to facilitate
> distributed querying without putting most of the burden on the servers.
>
> So, the primary difference between querying LDFs and the aforementioned
> Linked
> Data query processing is that querying LDFs is a form of distributed query
> processing, that is, some part of the execution of a given user query is
> distributed to LDF servers (which provide a limited form of query
> processing
> functionality). In contrast, Linked Data query processing  is _not_ a form
> of
> distributed query processing. Instead, for Linked Data query processing
> approaches, the whole execution of a query happens within the Linked Data
> query processing system (e.g., SQUIN), simply because these approaches do
> not
> assume / rely on server-side query processing functionality (servers in
> this
> setting are only required to answer URI lookup requests).
>
> Cheers,
> Olaf
>
>
> [1] Olaf Hartig: An Overview on Execution Strategies for Linked Data
> Queries.
> In Datenbankspektrum, 13(2) Jul. 2013.
> http://olafhartig.de/files/Hartig_LDQueryExec_DBSpektrum2013_Preprint.pdf
>
>
>
> > Thanks,
> >
> >
> > Martynas
> > graphityhq.com
> > ----------------------------- snip --------------------
>
>
>