group_by: Time GROUP BY operation

In clarkfitzg/RDataBenchmarks: Experiments evaluating the performance of different data processing techniques in R

Description

Internally this uses data.table, because it's fast and we want the speed.

Usage

group_by_local_shuffle(dir, nworkers = 3L,
  assign_groups = data_local_group_assign, group_fun = median)

greedy_group_assign(P, nworkers)

data_local_group_assign(P, w)

Arguments

dir	directory where data can be found
nworkers	number of workers
assign_groups	function to assign files and groups to workers, signature must match default
group_fun	function to apply to each group

Functions

• greedy_group_assign: Greedy scheduling to assign groups in a GROUP BY to workers

• data_local_group_assign: Data location aware scheduling to assign groups in a GROUP BY to workers

clarkfitzg/RDataBenchmarks documentation built on June 29, 2019, 11:38 p.m.