Details
| Original language | English |
|---|---|
| Title of host publication | Proceedings of the 34th ACM/SIGAPP Symposium on Applied Computing (SAC '19) |
| Place of Publication | New York |
| Publisher | Association for Computing Machinery (ACM) |
| Pages | 2267-2274 |
| Number of pages | 8 |
| ISBN (print) | 978-1-4503-5933-7 |
| Publication status | Published - 8 Apr 2019 |
| Event | 34th Annual ACM Symposium on Applied Computing, SAC 2019 - Limassol, Cyprus Duration: 8 Apr 2019 → 12 Apr 2019 |
Abstract
The current de-facto way to query the Web of Data is through the SPARQL protocol, where a client sends queries to a server through a SPARQL endpoint. Contrary to an HTTP server, providing and maintaining a robust and reliable endpoint requires a significant effort that not all publishers are willing or able to make. An alternative query evaluation method is through link traversal, where a query is answered by dereferencing online web resources (URIs) at real time. While several approaches for such a lookup-based query evaluation method have been proposed, there exists no analysis of the types (patterns) of queries that can be directly answered on the live Web, without accessing local or remote endpoints and without a-priori knowledge of available data sources. In this paper, we first provide a method for checking if a SPARQL query (to be evaluated on a SPARQL endpoint) can be answered through zero-knowledge link traversal (without accessing the endpoint), and analyse a large corpus of real SPARQL query logs for finding the frequency and distribution of answerable and non-answerable query patterns. Subsequently, we provide an algorithm for transforming answerable queries to SPARQL-LD queries that bypass the endpoints. We report experimental results about the efficiency of the transformed queries and discuss the benefits and the limitations of this query evaluation method.
Keywords
- Link Traversal, Linked Data, SPARQL, SPARQL-LD, Web of Data
ASJC Scopus subject areas
- Computer Science(all)
- Software
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Proceedings of the 34th ACM/SIGAPP Symposium on Applied Computing (SAC '19). New York: Association for Computing Machinery (ACM), 2019. p. 2267-2274.
Research output: Chapter in book/report/conference proceeding › Conference contribution › Research › peer review
}
TY - GEN
T1 - How Many and What Types of SPARQL Queries can be Answered through Zero-Knowledge Link Traversal?
AU - Fafalios, Pavlos
AU - Tzitzikas, Yannis
PY - 2019/4/8
Y1 - 2019/4/8
N2 - The current de-facto way to query the Web of Data is through the SPARQL protocol, where a client sends queries to a server through a SPARQL endpoint. Contrary to an HTTP server, providing and maintaining a robust and reliable endpoint requires a significant effort that not all publishers are willing or able to make. An alternative query evaluation method is through link traversal, where a query is answered by dereferencing online web resources (URIs) at real time. While several approaches for such a lookup-based query evaluation method have been proposed, there exists no analysis of the types (patterns) of queries that can be directly answered on the live Web, without accessing local or remote endpoints and without a-priori knowledge of available data sources. In this paper, we first provide a method for checking if a SPARQL query (to be evaluated on a SPARQL endpoint) can be answered through zero-knowledge link traversal (without accessing the endpoint), and analyse a large corpus of real SPARQL query logs for finding the frequency and distribution of answerable and non-answerable query patterns. Subsequently, we provide an algorithm for transforming answerable queries to SPARQL-LD queries that bypass the endpoints. We report experimental results about the efficiency of the transformed queries and discuss the benefits and the limitations of this query evaluation method.
AB - The current de-facto way to query the Web of Data is through the SPARQL protocol, where a client sends queries to a server through a SPARQL endpoint. Contrary to an HTTP server, providing and maintaining a robust and reliable endpoint requires a significant effort that not all publishers are willing or able to make. An alternative query evaluation method is through link traversal, where a query is answered by dereferencing online web resources (URIs) at real time. While several approaches for such a lookup-based query evaluation method have been proposed, there exists no analysis of the types (patterns) of queries that can be directly answered on the live Web, without accessing local or remote endpoints and without a-priori knowledge of available data sources. In this paper, we first provide a method for checking if a SPARQL query (to be evaluated on a SPARQL endpoint) can be answered through zero-knowledge link traversal (without accessing the endpoint), and analyse a large corpus of real SPARQL query logs for finding the frequency and distribution of answerable and non-answerable query patterns. Subsequently, we provide an algorithm for transforming answerable queries to SPARQL-LD queries that bypass the endpoints. We report experimental results about the efficiency of the transformed queries and discuss the benefits and the limitations of this query evaluation method.
KW - Link Traversal
KW - Linked Data
KW - SPARQL
KW - SPARQL-LD
KW - Web of Data
UR - http://www.scopus.com/inward/record.url?scp=85065649740&partnerID=8YFLogxK
U2 - 10.48550/arXiv.1901.04954
DO - 10.48550/arXiv.1901.04954
M3 - Conference contribution
AN - SCOPUS:85065649740
SN - 978-1-4503-5933-7
SP - 2267
EP - 2274
BT - Proceedings of the 34th ACM/SIGAPP Symposium on Applied Computing (SAC '19)
PB - Association for Computing Machinery (ACM)
CY - New York
T2 - 34th Annual ACM Symposium on Applied Computing, SAC 2019
Y2 - 8 April 2019 through 12 April 2019
ER -