Parallel-Correctness and Transferability for Conjunctive Queries
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.
Cite
@article{arxiv.1412.4030,
title = {Parallel-Correctness and Transferability for Conjunctive Queries},
author = {Tom J. Ameloot and Gaetano Geck and Bas Ketsman and Frank Neven and Thomas Schwentick},
journal= {arXiv preprint arXiv:1412.4030},
year = {2015}
}
Comments
30 pages