time travelling through dbpedia

Time travelling through DBpediaMiel Vander Sande

There is a huge amount of interesting information in DBpedia’s history.

What could we learn if we could easily query it?

Sustainable querying on fragments.dbpedia.org

Uniform access to DBpedia versions

Rewriting history: applying Memento to Triple Pattern Fragments

Time travelling through DBpedia

Use cases and opportunities

Sustainable querying on fragments.dbpedia.org

Uniform access to DBpedia versions

Rewriting history: applying Memento to Triple Pattern Fragments

Time travelling through DBpedia

Use cases and opportunities

Linked Data Fragments: hunting trade-offs between client & server.

high server costlow server cost

datadump

SPARQLendpoint

interface offered by the server

high availability low availabilityhigh bandwidth low bandwidthout-of-date data live data

low client costhigh client cost

DBpediaPages

low server cost

datadump

SPARQLquery results

high availabilitylive data

DBpediaPages

triple patternfragments

A triple pattern fragments interfaceis low-cost and enables clients to query.

A Triple Pattern Fragments interfaceacts as a gateway to an RDF source.

Client can only ask ?s ?p ?o patterns.

Decompose complex SPARQL querieson the client-side.

Low server cost, highly cacheable, but higher bandwidth and query time.

Usage is steadily increasing since the release in October 2014.

# Re

ques

ts

February 2015 September 2016

19.239.907

4.500.000

And still the API has 99.99% availability up to today.

Sustainable querying on fragments.dbpedia.org

Uniform access to DBpedia versions

Rewriting history: applying Memento to Triple Pattern Fragments

Time travelling through DBpedia

Use cases and opportunities

The Memento Framework lets you negotiate Web resources over time.

DBpedia pages are available through Memento since 2010 (v1.0).

Any client can transparently navigate to a prior version.

http://dbpedia.org/page/Joachim_Lambek

Any client can transparently navigate to a prior version.

http://dbpedia.mementodepot.org/memento/20090924000000/http://dbpedia.org/page/Joachim_Lambek

No updates since version 3.9 (2013) because of scalability problems.

1.0

Indexing Custom

Indexing time ~ 24 hours per version

Storage MongoDB

Space 383 Gb

# Versions 10 versions: 2.0 through 3.9

# Triples ~ 3 billion

Sustainable querying on fragments.dbpedia.org

Uniform access to DBpedia versions

Rewriting history: applying Memento to Triple Pattern Fragments

Time travelling through DBpedia

Use cases and opportunities

Directly compatible with Memento

datadump

SPARQLquery results

Queryable for the consumerSustainable for publisher

DBpediapages

triple patternfragments

The Triple Pattern Fragments trade-offalso pays off for archives.

Different HDT snapshots are exposed through an LDF server with Memento

http://fragments.dbpedia.org

(v2.0)

DBpedia pages are now available through a proxy.

http://dbpedia.org/resource/…

Space and time-to-publish significantly decreased.

1.0 2.0

Indexing Custom HDT-CPP

Indexing time ~ 24 hours per version ~ 4 hours per version

Storage MongoDB HDT binary files

Space 383 Gb 70 Gb

# Versions 10 versions: 2.0 through 3.9

12 versions: 2.0 through 2015

# Triples ~ 3 billion ~ 5 billion

Preparing the TPF client was simply adding an HTTP header.

Query EngineSPARQL Processing

Hypermedia Layer Fragments interaction

HTTP Layer Resource access

DBpedia 3.9

DBpedia 2015

303 Location 200 Content-Location (CORS)

ClientServer

GET Accept-Datetime

A self-descriptive interface results in a single datetime negotiation.

Query EngineSPARQL Processing

Hypermedia Layer Fragments interaction

HTTP Layer Resource access

DBpedia 3.9

DBpedia 2015

ClientServer

GET 200

Sustainable querying on fragments.dbpedia.org

Uniform access to DBpedia versions

Rewriting history: applying Memento to Triple Pattern Fragments

Time travelling through DBpedia

Use cases and opportunities

Querying history and the evolution of facts.

When did a researcher with name Hans Fichtner and born in Leipzig die?

Try it yourself: bit.ly/hansfichtner

bit.ly/hansfichtner-2012

What predicates were added between 2009 and 2014 to describe a person?

Analyze and profile changes in DBpedia.

Try it yourself: bit.ly/personpredicates-2009 bit.ly/personpredicates-2014

What works by cubists were known by DBpedia and VIAF in 2009?

Resolve out-of-sync issues between federated sources.

Try it yourself: bit.ly/workscubists-2009

bit.ly/workscubists

Sustainable querying on fragments.dbpedia.org

Uniform access to DBpedia versions

Rewriting history: applying Memento to Triple Pattern Fragments

Time travelling through DBpedia

Use cases and opportunities

Start digging into DBpedia’s history or host your own Linked Data archive!

github.com/LinkedDataFragmentsbit.ly/configuring-memento

linkeddatafragments.org mementoweb.org

Software

Documentation and specification

fragments.mementodepot.orgclient.linkeddatafragments.org

Use the archive on

Time travelling through DBpedia@Miel_vdsHerbert Van de SompelHarihar Shankar Lyudmila BalakirevaRuben Verborgh