Abstract
Query optimization that involves expensive predicates have received considerable attention in the database community. Typically, the output to a database query is a set of tuples that satisfy certain conditions, and, with expensive predicates, these conditions may be computationally costly to verify. In the simplest case, when the query looks for the set of tuples that simultaneously satisfy k expensive predicates, the problem reduces to ordering the evaluation of the predicates so as to minimize the time to output the set of tuples comprising the answer to the query.
Here, we give a simple and fast deterministic k-approximation algorithm for this problem, and prove that k is the best possible approximation ratio for a deterministic algorithm, even if exponential time algorithms are allowed. We also propose a randomized, polynomial time algorithm with expected approximation ratio \(1+\sqrt{2}/2\approx1.707\) for k=2, and prove that 3/2 is the best possible expected approximation ratio for randomized algorithms.
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
Preview
Unable to display preview. Download preview PDF.
Similar content being viewed by others
References
Bouganim, L., Fabret, F., Porto, F., Valduriez, P.: Processing queries with expensive functions and large objects in distributed mediator systems. In: Proc. 17th Intl. Conf. on Data Engineering, Heidelberg, Germany, April 2-6, pp. 91–98 (2001)
Charikar, M., Fagin, R., Guruswami, V., Kleinberg, J., Raghavan, P., Sahai, A.: Query strategies for priced information (extended abstract). In: Proceedings of the 32nd ACM Symposium on Theory of Computing, Portland, Oregon, May 21–23, pp. 582–591 (2000)
Chaudhuri, S., Shim, K.: Query optimization in the presence of foreign functions. In: Proc. 19th Intl. Conf. on VLDB, Dublin, Ireland, August 24-27, pp. 529–542 (1993)
Feder, T., Motwani, R., O’Callaghan, L., Panigrahy, R., Thomas, D.: Online distributed predicate evaluation (2003) (preprint)
Hellerstein, J.M.: Optimization techniques for queries with expensive methods. ACM Transactions on Database Systems 23(2), 113–157 (1998)
Laber, E., Carmo, R., Kohayakawa, Y.: Querying priced information in databases: The conjunctive case. Technical Report RT–MAC–2003–05, IME–USP, São Paulo, Brazil (July 2003)
Laber, E.S., Parekh, O., Ravi, R.: Randomized approximation algorithms for query optimization problems on two processors. In: Möhring, R.H., Raman, R. (eds.) ESA 2002. LNCS, vol. 2461, pp. 136–146. Springer, Heidelberg (2002)
Porto, F.: Estratégias para a Execução Paralela de Consultas em Bases de Dados Científicos Distribuídos. PhD thesis, Departamento de Informática, PUC-Rio (April 2001)
Yao, A.C.: Probabilistic computations: Toward a unified measure of complexity. In: 18th Annual Symposium on Foundations of Computer Science, Long Beach, Ca., USA, October 1977, pp. 222–227. IEEE Computer Society Press, Los Alamitos (1977)
Author information
Authors and Affiliations
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 2004 Springer-Verlag Berlin Heidelberg
About this paper
Cite this paper
Laber, S., Carmo, R., Kohayakawa, Y. (2004). Querying Priced Information in Databases: The Conjunctive Case. In: Farach-Colton, M. (eds) LATIN 2004: Theoretical Informatics. LATIN 2004. Lecture Notes in Computer Science, vol 2976. Springer, Berlin, Heidelberg. https://doi.org/10.1007/978-3-540-24698-5_5
Download citation
DOI: https://doi.org/10.1007/978-3-540-24698-5_5
Publisher Name: Springer, Berlin, Heidelberg
Print ISBN: 978-3-540-21258-4
Online ISBN: 978-3-540-24698-5
eBook Packages: Springer Book Archive