Conference Proceedings

Smooth Scan: Statistics-oblivious access paths

R Borovica-Gajic, S Idreos, A Ailamaki, M Zukowski, C Fraser

2015 IEEE 31st International Conference on Data Engineering | IEEE Press | Published : 2015

Abstract

© 2015 IEEE. Query optimizers depend heavily on statistics representing column distributions to create efficient query plans. In many cases, though, statistics are outdated or non-existent, and the process of refreshing statistics is very expensive, especially for ad-hoc workloads on ever bigger data. This results in suboptimal plans that severely hurt performance. The main problem is that any decision, once made by the optimizer, is fixed throughout the execution of a query. In particular, each logical operator translates into a fixed choice of a physical operator at run-time. In this paper, we advocate for continuous adaptation and morphing of physical operators throughout their lifetime, ..

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Grants

Awarded by European Union


Funding Acknowledgements

We would like to thank the organizers of the Dagstuhl seminar 12321 on "Robust query processing" for the introduction of robustness issues in query processing. In particular, we thank Goetz Graefe for his support throughout this work. We thank Danica Porobic for the discussions on the cost model part of the work, and Anshuman Dutt, the DIAS lab members and the reviewers for their constructive feedback. This work is partially funded by the European Union Seventh Framework Programme (ERC-2013-CoG), Grant No 617508 (ViDa).