This class holds settings to control how a Parquet file is read by ParquetFileWriter.
The parameters compression, compression_level, use_dictionary
and write_statistics` support various patterns:
The default NULL leaves 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
Unlike the high-level write_parquet, ParquetWriterProperties arguments
use the C++ defaults. Currently this means "uncompressed" rather than
"snappy" for the compression argument.
The ParquetWriterProperties$create() factory method instantiates the object
and takes the following arguments:
table: table to write (required)
version: Parquet version, "1.0" or "2.0". Default "1.0"
compression: Compression type, algorithm "uncompressed"
compression_level: Compression level; meaning depends on compression algorithm
use_dictionary: Specify if we should use dictionary encoding. Default TRUE
write_statistics: Specify if we should write statistics. Default TRUE
data_page_size: Set a target threshold for the approximate encoded
size of data pages within a column chunk (in bytes). Default 1 MiB.