LOD2 Webinar Series: LIMES ? Discovery of Links across Knowledge Bases
The 1st version of the LOD2 Stack has been published in September 2011 in the form of an LOD2 Stack demo and the downloadable LOD2 Stack virtual machine image – additional details and the instructions on installing the LOD2 Stack from scratch are available in the How-To-Start document. Born from the wish to make linking [...]

LOD2 Plenary Meeting: WebID and Authorization SIG
Today morning, we started the main LOD2 plenary meeting in Vienna. The first half day session the WebID special interest group discussed about WebID based single sign for the LDO2 stack and authorization. The challenge here is to provide a interoperable authorization layer which describe user, groups / roles and access to different parts of the stack as well as the managed knowledge bases. We agreed on the following short and long-time goals and activities: WebID registration service and stack internal authorization policy.

Features

RDF Parser / Serializer

Triple Storage

Erfurt uses a storage abstraction layer to access RDF stores as well as includes its own Zend DB based RDF store.

Storage Abstraction

At the moment, Erfurt implements two different interfaces for the storage abstraction: Zend DB and Virtuoso.

Access Control

Access Control can be managed based on Actions, Models / Graphs ans Statements (currently not in trunk). More Information can reviewed at the Access Control OntoWiki page.

Erfurt RDF Store (Zend DB)

The Erfurt RDF Store consists of an SPARQL to SQL rewriter and a corrsponding relational table layout.

Versioning

SPARQL Query / Update

Caching

The performance of triple stores is one of the major obstacles for the deployment of semantic technologies in many usage scenarios. In particular Semantic Web applications, which use triple stores as persistence backends, trade performance in for the advantage of flexibility with regard to information structuring. In order to get closer to the performance of relational database-backed Web applications, Erfurt provide a Caching solution for improving the performance of configured triple stores by caching query results and even complete application objects. The selective invalidation of cache objects, following updates of the underlying knowledge bases, is based on analysing the graph patterns of cached SPARQL queries in order to obtain information which updates will change the query result.
Erfurt uses this caching solution internal (if configured) for all needed SPARQL-Queries, but also provide an interface for the usage of applications based on this API.

Plugins / Trigger

Datagathering / Data Wrapper

Tutorial

Documentation

The Erfurt API Documentation is available at http://docs.ontowiki.net/api/

There are no files on this page. [Display files/form]

There is no comment on this page. [Display comments/form]

Information

Last Modification: 2011-05-18 15:43:53 by Ali Khalili