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arXiv · 1412.4030

Parallel-Correctness and Transferability for Conjunctive Queries

Tom J. Ameloot·Gaetano Geck·Bas Ketsman·Frank Neven·Thomas Schwentick
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Abstract

A dominant cost for query evaluation in modern massively distributed systems is the number of communication rounds. For this reason, there is a growing interest in single-round multiway join algorithms where data is first reshuffled over many servers and then evaluated in a parallel but communication-free way. The reshuffling itself is specified as a distribution policy. We introduce a correctness condition, called parallel-correctness, for the evaluation of queries w.r.t. a distribution policy. We study the complexity of parallel-correctness for conjunctive queries as well as transferability of parallel-correctness between queries. We also investigate the complexity of transferability for certain families of distribution policies, including, for instance, the Hypercube distribution.

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Tom J. Ameloot, Gaetano Geck, Bas Ketsman, Frank Neven, Thomas Schwentick. 2015-01-05. Parallel-Correctness and Transferability for Conjunctive Queries. https://arxiv.org/abs/1412.4030

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