- From: Alfredo Serafini <seralf@gmail.com>
- Date: Tue, 11 Mar 2014 13:31:41 +0100
- To: Ruben Verborgh <ruben.verborgh@ugent.be>
- Cc: public-lod Data <public-lod@w3.org>, "semantic-web@w3.org Web" <semantic-web@w3.org>
- Message-ID: <CADawF4NhHrEqPWoxwUSd9JW7R5q4fERM7C3UjrezQWCXcTmDpw@mail.gmail.com>
great! I have tried in the past the construction of a sort of "federated" Linked Data "cache" server, and from that experience I was looking for some library who decompose queries in order to maximise triples re-using. If I am not wrong is what you are doing here? Most of of all I am curious about the methods: do you propose this approach as a pattern more than a technologic solution? If I undertand correctly the idea, this seems to me great, and can be expanded in many ways, maybe also introducing a sort of "linked hypermedia" layer. I'll follow the updates! :-) 2014-03-11 13:06 GMT+01:00 Ruben Verborgh <ruben.verborgh@ugent.be>: > Dear Semantic Web and Linked Data enthusiasts, > > If you're curious about new ways to query Linked Data, > you might like our Linked Data Fragments client. > It lets your browser execute SPARQL queries over Web data > in a scalable way: http://client.linkeddatafragments.org/ > > Today's answer to Web querying consists of SPARQL endpoints. > Publishers of data sets offer a public endpoint, which > answers highly specific questions for any client. Unfortunately, > the availability of public SPARQL endpoints is problematic [1] – > and thus so is the availability of publicly queryable datasets. > We cannot rely on them for building applications, and that's a pity. > > It is not an issue of performance but an inherent architectural issue: > making a public server responsible for arbitrarily complex requests > doesn't work on a Web scale. We have to create more simple servers, > only answering simple questions that don't endanger availability. > Yet at the same time, the dataset should remain easily queryable. > > This is the goal of the Linked Data Fragments project [2]. > “Linked Data Fragments” is a term for all ways to offer parts of a dataset: > - SPARQL results are (precise but expensive) Linked Data Fragments. > - Data dumps are (huge but straightforward) Linked Data Fragments. > Between those two extremes, an underexplored range of fragments exists. > > We propose a new type called “basic Linked Data Fragments”, > which partitions a dataset in all its basic triple patterns. > This reconciles the need for queryable public datasets > with the availability demands of Web applications. > A basic Linked Data Fragments server with well-known datasets > is available online [3] (and so is its source code [4]). > > Try our online client [5] that answers SPARQL queries > using only basic Linked Data Fragments (source code [6]). > It works up to two magnitudes faster than Linked Data Querying [7] > because servers offers those fragments that assist client-side querying – > without needing to solve expensive queries at the server side. > > Basic Linked Data Fragments are not a definitive answer; > there are many other types of fragments to explore. > However, you might be surprised to see quite acceptable query times, > and – most importantly – high availability and scalability. > > Read more on Linked Data Fragments on the website > http://linkeddatafragments.org/ and discover all details > in our forthcoming LDOW2014 publication [8]. > > Looking forward to your feedback! > > Best regards, > > Ruben Verborgh > Ghent University – iMinds, Belgium > > > [1] http://sw.deri.org/~aidanh/docs/epmonitorISWC.pdf > [2] http://linkeddatafragments.org/ > [3] http://data.linkeddatafragments.org/ > [4] https://github.com/LinkedDataFragments/Server > [5] http://client.linkeddatafragments.org/ > [6] https://github.com/LinkedDataFragments/Client > [7] > https://cs.uwaterloo.ca/~ohartig/files/Hartig_LDQueryExec_DBSpektrum2013_Preprint.pdf > [8] http://linkeddatafragments.org/publications/ldow2014.pdf > >
Received on Tuesday, 11 March 2014 12:32:09 UTC