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DPLA is working on moving to a more RDF-aware stack, including Marmotta[1] as a triplestore, Linked Data Platform server, and Linked Data cache layer. You can check out our data model[2], which we use as a common format for special collections/archives/museum metadata aggregated from our partners. Marmotta gives us RDF persistence with graph query via SPARQL, and a REST interface via LDP[3]. Most/all of our actual interactions with the data are mediated by ActiveTriples[4], an ORM-like interface to RDF resources. From there, it's just like any other application, with the benefits (and pitfalls) offered by a graph model, Open World, URIs, etc... becoming tangible from time to time. [1] http://marmotta.apache.org/ [2] http://dp.la/info/wp-content/uploads/2013/04/DPLA-MAP-V3.1-2.pdf [3] http://www.w3.org/TR/ldp/ [4] https://github.com/ActiveTriples/ActiveTriples On Fri, Dec 19, 2014 at 7:32 AM, Forrest, Stuart <[log in to unmask]> wrote: > Thanks Jeff > > Interesting concept, can you give me any examples of their usage, what > kinds of data etc.? > > Thanks > > > ================================================================================ > Stuart Forrest PhD > Library Systems Specialist > Beaufort County Library > 843 255 6450 > [log in to unmask] > > http://www.beaufortcountylibrary.org > > For Leisure, For Learning, For Life > > > > > -----Original Message----- > From: Code for Libraries [mailto:[log in to unmask]] On Behalf Of > Mixter,Jeff > Sent: Friday, December 19, 2014 10:20 AM > To: [log in to unmask] > Subject: Re: [CODE4LIB] rdf triplestores > > A triplestore is basically a database backend for RDF triples. The major > benefit is that it allows for SPARQL querying. You could imagine a > triplestore as being the same thing as a relational database that can be > queried with SQL. > > The drawback that I have run into is that unless you have unlimited > hardware, triplestores can run into scaling problems (when you are looking > at hundreds of millions or billions of triples). This is a problem when you > want to search for data. For searching I use a hybrid Elasticsearch (i.e. > Lucene) index for the string literals and the go out to the triplestore to > query for the data. > > If you are looking to use a triplestore it is important to distinguish > between search and query. > > Triplestore are really good for query but not so good for search. The > basic problem with search is that is it mostly string based and this > requires a regular expression query in SPARQL which is expensive from a > hardware perspective. > > There are a few triple stores that use a hybrid model. In particular Jena > Fuseki (http://jena.apache.org/documentation/query/text-query.html) > > Thanks, > > Jeff Mixter > Research Support Specialist > OCLC Research > 614-761-5159 > [log in to unmask] > > ________________________________________ > From: Code for Libraries <[log in to unmask]> on behalf of Forrest, > Stuart <[log in to unmask]> > Sent: Friday, December 19, 2014 10:00 AM > To: [log in to unmask] > Subject: Re: [CODE4LIB] rdf triplestores > > Hi All > > My question is what do you guys use triplestores for? > > Thanks > Stuart > > > > ================================================================================ > Stuart Forrest PhD > Library Systems Specialist > Beaufort County Library > 843 255 6450 > [log in to unmask] > > http://www.beaufortcountylibrary.org > > For Leisure, For Learning, For Life > > > > -----Original Message----- > From: Code for Libraries [mailto:[log in to unmask]] On Behalf Of > Stefano Bargioni > Sent: Monday, November 11, 2013 8:53 AM > To: [log in to unmask] > Subject: Re: [CODE4LIB] rdf triplestores > > My +1 for Joseki. > sb > > On 11/nov/2013, at 06.12, Eric Lease Morgan wrote: > > > What is your favorite RDF triplestore? > > > > I am able to convert numerous library-related metadata formats into > RDF/XML. In a minimal way, I can then contribute to the Semantic Web by > simply putting the resulting files on an HTTP file system. But if I were to > import my RDF/XML into a triplestore, then I could do a lot more. Jena > seems like a good option. So does Openlink Virtuoso. > > > > What experience do y'all have with these tools, and do you know how to > import RDF/XML into them? > > > > -- > > Eric Lease Morgan > > >