Write Parquet file to diskSource:
Parquet is a columnar storage file format. This function enables you to write Parquet files from R.
write_parquet( x, sink, chunk_size = NULL, version = "2.4", compression = default_parquet_compression(), compression_level = NULL, use_dictionary = NULL, write_statistics = NULL, data_page_size = NULL, use_deprecated_int96_timestamps = FALSE, coerce_timestamps = NULL, allow_truncated_timestamps = FALSE )
A string file path, URI, or OutputStream, or path in a file system (
how many rows of data to write to disk at once. This directly corresponds to how many rows will be in each row group in parquet. If
NULL, a best guess will be made for optimal size (based on the number of columns and number of rows), though if the data has fewer than 250 million cells (rows x cols), then the total number of rows is used.
parquet version: "1.0", "2.0" (deprecated), "2.4" (default), "2.6", or "latest" (currently equivalent to 2.6). Numeric values are coerced to character.
compression algorithm. Default "snappy". See details.
compression level. Meaning depends on compression algorithm
logical: use dictionary encoding? Default
logical: include statistics? Default
Set a target threshold for the approximate encoded size of data pages within a column chunk (in bytes). Default 1 MiB.
logical: write timestamps to INT96 Parquet format, which has been deprecated? Default
Cast timestamps a particular resolution. Can be
NULL, "ms" or "us". Default
logical: Allow loss of data when coercing timestamps to a particular resolution. E.g. if microsecond or nanosecond data is lost when coercing to "ms", do not raise an exception. Default
Due to features of the format, Parquet files cannot be appended to. If you want to use the Parquet format but also want the ability to extend your dataset, you can write to additional Parquet files and then treat the whole directory of files as a Dataset you can query. See the dataset article for examples of this.
write_statistics support various patterns:
NULLleaves the parameter unspecified, and the C++ library uses an appropriate default for each column (defaults listed above)
A single, unnamed, value (e.g. a single string for
compression) applies to all columns
An unnamed vector, of the same size as the number of columns, to specify a value for each column, in positional order
A named vector, to specify the value for the named columns, the default value for the setting is used when not supplied
compression argument can be any of the following (case insensitive):
"uncompressed", "snappy", "gzip", "brotli", "zstd", "lz4", "lzo" or "bz2".
Only "uncompressed" is guaranteed to be available, but "snappy" and "gzip"
are almost always included. See
The default "snappy" is used if available, otherwise "uncompressed". To
disable compression, set
compression = "uncompressed".
Note that "uncompressed" columns may still have dictionary encoding.
ParquetFileWriter for a lower-level interface to Parquet writing.