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Summary: Robustness in Automatic Physical Database Design
Kareem El Gebaly
Ericsson
kareem.gebaly@ericsson.com
Ashraf Aboulnaga
University of Waterloo
ashraf@cs.uwaterloo.ca
ABSTRACT
Automatic physical database design tools rely on "what-if"
interfaces to the query optimizer to estimate the execution
time of the training query workload under different candi-
date physical designs. The tools use these what-if inter-
faces to recommend physical designs that minimize the es-
timated execution time of the input training workload. In
this paper, we argue that minimizing estimated execution
time alone can lead to designs with inherent problems. In
particular, if the optimizer makes an error in estimating the
execution time of some workload queries, then the recom-
mended physical design may actually harm the workload
instead of benefiting it. In this sense, the physical design is
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