2014/01/01 by Riko Jacob, Tobias Lieber, Nodari Sitchinava · 5 citations
Computer Science · #Auxiliary memory #Complexity and Algorithms in Graphs #Computational complexity theory #Distributed systems and fault tolerance #Dual (grammatical number) #Optimization and Search Problems #Range (aeronautics) #Ranking (information retrieval) #Upper and lower bounds #cs.DS
paper · pdf · doi:10.1007/978-3-662-44465-8_33
published in Lecture notes in computer science, 384-395 (Springer Science+Business Media)
openalex publication_date 2014/01/01 · arxiv created 2014/06/12 · arxiv updated 2014/09/08 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We study the problem of list ranking in the parallel external memory (PEM) model. We observe an interesting dual nature for the hardness of the problem due to limited information exchange among the processors about the structure of the list, on the one hand, and its close relationship to the problem of permuting data, which is known to be hard for the external memory models, on the other hand. By carefully defining the power of the computational model, we prove a permuting lower bound in the PEM model. Furthermore, we present a stronger Ω(log2 N) lower bound for a special variant of the problem and for a specific range of the model parameters, which takes us a step closer toward proving a non-trivial lower bound for the list ranking problem in the bulk-synchronous parallel (BSP) and MapReduce models. Finally, we also present an algorithm that is tight for a larger range of parameters of the model than in prior work.