disk.frame (version 0.8.3)

rechunk: Increase or decrease the number of chunks in the disk.frame

Description

Increase or decrease the number of chunks in the disk.frame

Usage

rechunk(
  df,
  nchunks = disk.frame::nchunks(df),
  outdir = attr(df, "path", exact = TRUE),
  shardby = NULL,
  overwrite = TRUE
)

Arguments

df

the disk.frame to rechunk

nchunks

number of chunks

outdir

the output directory

shardby

the shardkeys

overwrite

overwrite the output directory

Examples

# create a disk.frame with 2 chunks in tempdir()
cars.df = as.disk.frame(cars, nchunks = 2)

# re-chunking cars.df to 3 chunks, done "in-place" to the same folder as cars.df
rechunk(cars.df, 3)

new_path = tempfile(fileext = ".df")
# re-chunking cars.df to 4 chunks, shard by speed, and done "out-of-place" to a new directory
cars2.df = rechunk(cars.df, 4, outdir=new_path, shardby = "speed")

# clean up cars.df
delete(cars.df)
delete(cars2.df)