Abstract
In this paper we present a model of functional access to data that, we argue, is suitable for modeling a class of data repositories characterized by functional access, such as web sites. We discuss the problem of modeling such data sources as a set of relations, of determining whether a given query expressed on these relations can be translated into a combination of functions defined by the data sources, and of finding an optimal plan to do so.
We show that, if the data source is modeled as a single relation, an optimal plan can be found in a time linear in the number of functions in the source but, if the source is modeled as a number of relations that can be joined, finding the optimal plan is NP-hard.
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References
Damiani, E., Tanca, L.: Semantic approaches to structuring and querying web sites. In: DS-7 (1997)
Liu, Z., Li, F., Ng, W.K.: Wiccap data model: Mapping physical websites to logical views. In: Spaccapietra, S., March, S.T., Kambayashi, Y. (eds.) ER 2002. LNCS, vol. 2503, pp. 120–134. Springer, Heidelberg (2002)
da Silva, S., Evangelista Filha, I.M., Laender, A.H.F., Embley, D.W.: Representing and querying semistructured web data using nested tables with structural variants. In: Spaccapietra, S., March, S.T., Kambayashi, Y. (eds.) ER 2002. LNCS, vol. 2503, pp. 135–151. Springer, Heidelberg (2002)
Zadorozhny, V., Raschid, L., Vidal, M.-E., Urhan, T., Bright, L.: Efficient evaluation of queries in a mediator for websources. In: Proceedings of ACM SIGMOD (2002)
Santini, S.: Notes on a relational model of functional data sources. tech. rep., BIRN-CC, University of California, San Diego (2003), http://ssantini.ucsd.edu/personal/bibliography/all-by-year/2003/s426long.pdf
Yerneni, R., Li, C., Garcia-Molina, H., Ullman, J.: Computing capabilities of mediators. In: Proceedings of ACM SIGMOD, pp. 443–454 (1999)
Li, Z., Chen, H.: Computing strong/weak bisimulation equivalences and observation congruence for value-passing processes. In: Cleaveland, W.R. (ed.) TACAS 1999. LNCS, vol. 1579, pp. 300–314. Springer, Heidelberg (1999)
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Santini, S., Gupta, A. (2004). Modeling Functional Data Sources as Relations. In: Atzeni, P., Chu, W., Lu, H., Zhou, S., Ling, TW. (eds) Conceptual Modeling – ER 2004. ER 2004. Lecture Notes in Computer Science, vol 3288. Springer, Berlin, Heidelberg. https://doi.org/10.1007/978-3-540-30464-7_6
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DOI: https://doi.org/10.1007/978-3-540-30464-7_6
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