Querying over Federated SPARQL Endpoints ---A State of the Art Survey

TL;DR

This survey reviews current methods for querying distributed Linked Data via federated SPARQL endpoints, compares existing frameworks, and discusses their limitations to guide future research.

Contribution

It provides a comprehensive overview and comparison of federated SPARQL frameworks, highlighting gaps and suggesting new research directions.

Findings

Existing frameworks vary in scalability and performance.

Many frameworks lack efficient query optimization.

Identified gaps suggest need for improved federation techniques.

Abstract

The increasing amount of Linked Data and its inherent distributed nature have attracted significant attention throughout the research community and amongst practitioners to search data, in the past years. Inspired by research results from traditional distributed databases, different approaches for managing federation over SPARQL Endpoints have been introduced. SPARQL is the standardised query language for RDF, the default data model used in Linked Data deployments and SPARQL Endpoints are a popular access mechanism provided by many Linked Open Data (LOD) repositories. In this paper, we initially give an overview of the federation framework infrastructure and then proceed with a comparison of existing SPARQL federation frameworks. Finally, we highlight shortcomings in existing frameworks, which we hope helps spawning new research directions.