An Alignment-Driven Approach for Constructing SPARQL Federated Queries

Abstract

Integrating complementary information across distributed SPARQL endpoints remains a significant challenge. While query federation enables access across multiple endpoints, constructing federated queries requires both SPARQL expertise and knowledge of the underlying ontological schemas. Current query rewriting techniques primarily focus on vocabulary translation to retrieve equivalent data, often overlooking the integration of complementary information spread across sources. To address these limitations, we propose an alignment-driven approach that assists users in constructing federated queries by leveraging ontology alignments. Our approach joins class paths – user-selected sequences of ontology classes and relationships – from source and target ontologies, guided by alignment-based filtering, into a unified path that serves as the foundation for generating federated SPARQL queries capturing complementary aspects of the user’s intent. An experimental evaluation using OAEI Conference track datasets demonstrates that the generated queries consistently match reference queries in both structure and data retrieval across simple and complex mapping types, confirming the approach’s effectiveness in integrating complementary data from heterogeneous sources.