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Title: A Near-Optimal Parallel Algorithm for Joining Binary Relations
We present a constant-round algorithm in the massively parallel computation(MPC) model for evaluating a natural join where every input relation has twoattributes. Our algorithm achieves a load of $\tilde{O}(m/p^{1/\rho})$ where$m$ is the total size of the input relations, $p$ is the number of machines,$\rho$ is the join's fractional edge covering number, and $\tilde{O}(.)$ hidesa polylogarithmic factor. The load matches a known lower bound up to apolylogarithmic factor. At the core of the proposed algorithm is a new theorem(which we name the "isolated cartesian product theorem") that provides freshinsight into the problem's mathematical structure. Our result implies that thesubgraph enumeration problem, where the goal is to report all the occurrencesof a constant-sized subgraph pattern, can be settled optimally (up to apolylogarithmic factor) in the MPC model.  more » « less
Award ID(s):
1907997 1954222
Author(s) / Creator(s):
; ;
Date Published:
Journal Name:
Logical Methods in Computer Science
Volume 18, Issue 2
Medium: X
Sponsoring Org:
National Science Foundation
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