Author_Institution :
Comput. Sci. Lab., SRI Int., USA
fDate :
26 Feb-1 Mar 1996
Abstract :
Query folding refers to the activity of determining if and how a query can be answered using a given set of resources, which might be materialized views, cached results of previous queries, or queries answerable by other databases. We investigate query folding in the context where queries and resources are conjunctive queries. We develop an exponential time algorithm that finds all complete or partial foldings, and a polynomial time algorithm for the subclass of acyclic conjunctive queries. Our results can be applied to query optimization in centralized databases, to query processing in distributed databases, and to query answering in federated databases
Keywords :
computational complexity; graph theory; query processing; acyclic conjunctive queries; cached results; centralized databases; conjunctive queries; distributed databases; exponential time algorithm; federated databases; materialized views; partial foldings; polynomial time algorithm; query answering; query folding; query optimization; query processing; Computer science; Contracts; Distributed databases; Drugs; Insurance; Intrusion detection; Laboratories; Polynomials; Query processing; Variable speed drives;
Conference_Titel :
Data Engineering, 1996. Proceedings of the Twelfth International Conference on
Conference_Location :
New Orleans, LA
Print_ISBN :
0-8186-7240-4
DOI :
10.1109/ICDE.1996.492088
