Abstract
Database users may be frustrated by no answers returned when they pose a query on the database. In this paper, we study the problem of relaxing queries on RDF databases in order to acquire approximate answers. We address two problems for efficient query relaxation. First, to ensure the quality of answers, we compute the similarities of relaxed queries with regard to the original query and use them to score the potential relevant answers. We also propose the algorithm to get most relevant answers as soon as possible. Second, to optimise query relaxation process, we characterize a type of unnecessary relaxed queries which do not contribute to the final results and propose the method to prune them from the query relaxation graph. At last, we implement and experimentally evaluate our approach.
Access provided by Autonomous University of Puebla. Download to read the full chapter text
Chapter PDF
Similar content being viewed by others
References
Broekstra, J., Kampman, A., van Harmelen, F.: Sesame: A Generic Architecture for Storing and Querying RDF and RDF Schema. In: International Semantic Web Conference, pp. 54–68 (2002)
Guha, R.: rdfDB: An RDF Database, http://www.guha.com/rdfdb/
SPARQL Query Language for RDF, http://www.w3.org/TR/rdf-sparql-query/
Hurtado, C.A., Poulovassilis, A., Wood, P.T.: A Relaxed Approach to RDF Querying. In: International Semantic Web Conference, pp. 314–328 (2006)
Fagin, R., Lotem, A., Naor, M.: Optimal Aggregation Algorithms for Middleware. In: PODS (2001)
Fagin, R.: Fuzzy Queries in Multimedia Database Systems. In: PODS, pp. 1–10 (1998)
Carey, M.J., Kossmann, D.: On Saying “Enough Already!” in SQL. In: SIGMOD Conference, pp. 219–230 (1997)
Bruno, N., Chaudhuri, S., Gravano, L.: Top-k selection queries over relational databases: Mapping strategies and performance evaluation. ACM Trans. Database Syst. 27(2), 153–187 (2002)
Chen, C.-M., Ling, Y.: A Sampling-Based Estimator for Top-k Query. In: ICDE, pp. 617–627 (2002)
Hristidis, V., Koudas, N., Papakonstantinou, Y.: PREFER: A System for the Efficient Execution of Multi-parametric Ranked Queries. In: SIGMOD Conference, pp. 259–270 (2001)
Natsev, A., Chang, Y.-C., Smith, J.R., Li, C.-S., Vitter, J.S.: Supporting Incremental Join Queries on Ranked Inputs. In: Proc. of the 27th International Conference on Very Large Data Bases, pp. 281–290 (2001)
Godfrey, P.: Minimization in Cooperative Response to Failing Database Queries. Int. J. Cooperative Inf. Syst. 6(2), 95–149 (1997)
Chu, W.W., Yang, H., Chiang, K., Minock, M., Chow, G., Larson, C.: CoBase.: A Scalable and Extensible Cooperative Information System. J. Intell. Inf. Syst. 6(2/3), 223–259 (1996)
Kleinberg, J.M.: Authoritative Sources in a Hyperlinked Environment. J. ACM 46(5), 604–632 (1999)
Amer-Yahia, S., Cho, S., Srivastava, D.: Tree Pattern Relaxation. In: Jensen, C.S., Jeffery, K.G., Pokorný, J., Šaltenis, S., Bertino, E., Böhm, K., Jarke, M. (eds.) EDBT 2002. LNCS, vol. 2287, pp. 496–513. Springer, Heidelberg (2002)
Guo, Y., Pan, Z., Heflin, J.: An Evaluation of Knowledge Base Systems for Large OWL Datasets. In: International Semantic Web Conference, pp. 274–288 (2004)
Jena SDB, http://jena.hpl.hp.com/wiki/SDB
Author information
Authors and Affiliations
Editor information
Rights and permissions
Copyright information
© 2008 Springer-Verlag Berlin Heidelberg
About this paper
Cite this paper
Huang, H., Liu, C., Zhou, X. (2008). Computing Relaxed Answers on RDF Databases. In: Bailey, J., Maier, D., Schewe, KD., Thalheim, B., Wang, X.S. (eds) Web Information Systems Engineering - WISE 2008. WISE 2008. Lecture Notes in Computer Science, vol 5175. Springer, Berlin, Heidelberg. https://doi.org/10.1007/978-3-540-85481-4_14
Download citation
DOI: https://doi.org/10.1007/978-3-540-85481-4_14
Publisher Name: Springer, Berlin, Heidelberg
Print ISBN: 978-3-540-85480-7
Online ISBN: 978-3-540-85481-4
eBook Packages: Computer ScienceComputer Science (R0)