language: en

Semantic Query Caching for Heterogeneous Databases

Parke Godfrey
U.S. Army Research Laboratory
2800 Powder Mill Road Adelphi, Maryland 20783-1197 U.S.A.
godfrey@arl.mil
Jarek Gryz
Department of Computer Science York University
Toronto, Ontario M3J 1P3 Canada
jarek@cs.yorku.ca

Abstract Query caching can play a vital role in heterogeneous, multi-database environments. Answers to a query that are available in cache at the local client can be returned to the user quickly, while the rest of the query is evaluated. The use of caches can optimize query evaluation. By caching certain sensitive data locally, caches can be used to answer the parts of queries that involve the sensitive data, so it need not be shipped across the network. Most prior cache schemes have been tuple-based or page-based. It is unclear, however, how these might be adapted for multi-databases. We explore a more flexible semantic query caching (SQC) approach. In SQC, caches are the answer sets of previous queries, labeled by the query expressions that produced them. We promote developing the technology, based on logic, to manipulate semantic caches, to determine when and how caches can be used to answer subsequent queries, and to optimize via cache use.

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[Proceedings of the 4th KRDB Workshop Athens, Greece, 30-August-1997 (F. Baader, M.A. Jeusfeld, W. Nutt, eds.)]

1 Introduction