write_feather {arrow}

Write a Feather file (an Arrow IPC file)

Description

Feather provides binary columnar serialization for data frames. It is designed to make reading and writing data frames efficient, and to make sharing data across data analysis languages easy. write_feather() can write both the Feather Version 1 (V1), a legacy version available starting in 2016, and the Version 2 (V2), which is the Apache Arrow IPC file format. The default version is V2. V1 files are distinct from Arrow IPC files and lack many features, such as the ability to store all Arrow data tyeps, and compression support. write_ipc_file() can only write V2 files.

Usage

write_feather(
  x,
  sink,
  version = 2,
  chunk_size = 65536L,
  compression = c("default", "lz4", "lz4_frame", "uncompressed", "zstd"),
  compression_level = NULL
)

write_ipc_file(
  x,
  sink,
  chunk_size = 65536L,
  compression = c("default", "lz4", "lz4_frame", "uncompressed", "zstd"),
  compression_level = NULL
)

Arguments

x

data.frame, RecordBatch, or Table

sink

A string file path, connection, URI, or OutputStream, or path in a file system (SubTreeFileSystem)

version

integer Feather file version, Version 1 or Version 2. Version 2 is the default.

chunk_size

For V2 files, the number of rows that each chunk of data should have in the file. Use a smaller chunk_size when you need faster random row access. Default is 64K. This option is not supported for V1.

compression

Name of compression codec to use, if any. Default is "lz4" if LZ4 is available in your build of the Arrow C++ library, otherwise "uncompressed". "zstd" is the other available codec and generally has better compression ratios in exchange for slower read and write performance. "lz4" is shorthand for the "lz4_frame" codec. See codec_is_available() for details. TRUE and FALSE can also be used in place of "default" and "uncompressed". This option is not supported for V1.

compression_level

If compression is "zstd", you may specify an integer compression level. If omitted, the compression codec's default compression level is used.

Value

The input x, invisibly. Note that if sink is an OutputStream, the stream will be left open.

See Also

RecordBatchWriter for lower-level access to writing Arrow IPC data.

Schema for information about schemas and metadata handling.

Examples

# We recommend the ".arrow" extension for Arrow IPC files (Feather V2).
tf1 <- tempfile(fileext = ".feather")
tf2 <- tempfile(fileext = ".arrow")
tf3 <- tempfile(fileext = ".arrow")
on.exit({
  unlink(tf1)
  unlink(tf2)
  unlink(tf3)
})
write_feather(mtcars, tf1, version = 1)
write_feather(mtcars, tf2)
write_ipc_file(mtcars, tf3)