- From: Muhammad Saleem <saleem.muhammd@gmail.com>
- Date: Wed, 19 Mar 2014 15:55:31 +0100
- To: Olaf Hartig <ohartig@uwaterloo.ca>
- Cc: public-lod@w3.org, "semantic-web@w3.org Web" <semantic-web@w3.org>, Martynas Jusevičius <martynas@graphity.org>
- Message-ID: <CAKHFcRDN2z+3Uv+k=3SBt4PMYCewWdEfSxoYMxh0-XnWrX25Pw@mail.gmail.com>
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 JuseviÄius 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 -------------------- > > >
Received on Wednesday, 19 March 2014 14:56:00 UTC