Lehrgebiet Informationssysteme

FB Informatik

LG IS

AG DBIS

(C) AG DBIS

Database Caching – Towards a Cost Model for Populating Cache Groups

Theo Härder, Andreas Bühmann

University of Kaiserslautern
P.O. Box 3049, 67653 Kaiserslautern, Germany
e-mail: {haerder, buehmann}@informatik.uni-kl.de

Full paper (PDF version, SpringerLink)

Abstract:

Web caching keeps single Web objects ready somewhere in caches in the user-to-server path, whereas database caching uses full-fledged database management systems as caches to adaptively maintain sets of records from a remote database and to evaluate queries on them. Using so-called cache groups, we introduce the new concept of constraint-based database caching. These cache groups are constructed from parameterized cache constraints, and their use is based on the key concepts of value and domain completeness. We show how cache constraints affect the correctness of query evaluations in the cache and which optimizations they allow. Cache groups supporting practical applications must exhibit controllable load behavior for which we identify necessary conditions. For such safe cache groups, the cost trade-off for record loading and predicate evaluation saving has to be observed during their design. Therefore, we analyze their load overhead and propose a population estimation algorithm to be used for a cache group advisor. Finally, we summarize our results and comment on future research problems.

Published in: Advances in Databases and Information Systems: 8th East European Conference (ADBIS 2004), Budapest, Hungary, Sep. 2004, LNCS 3255, Springer, pp. 215-229.