Abstract
Traditional information search in which queries are posed against a known and rigid schema over a structured database is shifting towards a Web scenario in which exposed schemas are vague or absent and data comes from heterogeneous sources. In this framework, query answering cannot be precise and needs to be relaxed, with the goal of matching user requests with accessible data. In this paper, we propose a logical model and an abstract query language as a foundation for querying data sets with vague schemas. Our approach takes advantages of the availability of taxonomies, that is, simple classifications of terms arranged in a hierarchical structure. The model is a natural extension of the relational model in which data domains are organized in hierarchies, according to different levels of generalization. The query language is a conservative extension of relational algebra where special operators allow the specification of relaxed queries over vaguely structured information. We study equivalence and rewriting properties of the query language that can be used for query optimization.
This is a preview of subscription content, log in via an institution to check access.
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
Preview
Unable to display preview. Download preview PDF.
References
Amer-Yahia, S., Lakshmanan, L.V.S., Pandit, S.: Flexpath: Flexible structure and full-text querying for XML. In: Proc. of SIGMOD, pp. 83–94 (2004)
Balke, W.-T., Wagner, M.: Through different eyes: assessing multiple conceptual views for querying web services. In: Proc. of WWW, pp. 196–205 (2004)
Broder, A.Z., Fontoura, M., Josifovski, V., Riedel, L.: A semantic approach to contextual advertising. In: Proc. of SIGIR, pp. 559–566 (2007)
Chen, Y.-Y., Suel, T., Markowetz, A.: Efficient query processing in geographic web search engines. In: Proc. of SIGMOD, pp. 277–288 (2006)
Dong, X., Halevy, A.Y.: Malleable schemas: A preliminary report. In: Proc. of WebDB, pp. 139–144 (2005)
Fagin, R., Guha, R.V., Kumar, R., Novak, J., Sivakumar, D., Tomkins, A.: Multi-structural databases. In: Proc. of PODS, pp. 184–195 (2005)
Fontoura, M., Josifovski, V., Kumar, R., Olston, C., Tomkins, A., Vassilvitskii, S.: Relaxation in text search using taxonomies. In: Proc. of VLDB, vol. 1(1), pp. 672–683 (2008)
Koudas, N., Li, C., Tung, A.K.H., Vernica, R.: Relaxing join and selection queries. In: Proc. of VLDB, pp. 199–210 (2006)
Li, Y., Yang, H., Jagadish, H.V.: NaLIX: A generic natural language search environment for XML data. TODS, art. 30 32(4) (2007)
Martinenghi, D., Torlone, R.: Querying Context-Aware Databases. In: Proc. of FQAS, pp. 76–87 (2009)
Zhou, X., Gaugaz, J., Balke, W., Nejdl, W.: Query relaxation using malleable schemas. In: Proc. of SIGMOD, pp. 545–556 (2007)
Author information
Authors and Affiliations
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 2010 Springer-Verlag Berlin Heidelberg
About this paper
Cite this paper
Martinenghi, D., Torlone, R. (2010). Querying Databases with Taxonomies. In: Parsons, J., Saeki, M., Shoval, P., Woo, C., Wand, Y. (eds) Conceptual Modeling – ER 2010. ER 2010. Lecture Notes in Computer Science, vol 6412. Springer, Berlin, Heidelberg. https://doi.org/10.1007/978-3-642-16373-9_27
Download citation
DOI: https://doi.org/10.1007/978-3-642-16373-9_27
Publisher Name: Springer, Berlin, Heidelberg
Print ISBN: 978-3-642-16372-2
Online ISBN: 978-3-642-16373-9
eBook Packages: Computer ScienceComputer Science (R0)