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Format-specific scan options

Source: R/dataset-format.R
FragmentScanOptions.Rd

A FragmentScanOptions holds options specific to a FileFormat and a scan operation.

Factory

FragmentScanOptions$create() takes the following arguments:

  • format: A string identifier of the file format. Currently supported values:

    • "parquet"

    • "csv"/"text", aliases for the same format.

  • ...: Additional format-specific options

    format = "parquet":

    • use_buffered_stream: Read files through buffered input streams rather than loading entire row groups at once. This may be enabled to reduce memory overhead. Disabled by default.

    • buffer_size: Size of buffered stream, if enabled. Default is 8KB.

    • pre_buffer: Pre-buffer the raw Parquet data. This can improve performance on high-latency filesystems. Disabled by default. format = "text": see CsvConvertOptions. Note that options can only be specified with the Arrow C++ library naming. Also, "block_size" from CsvReadOptions may be given.

It returns the appropriate subclass of FragmentScanOptions (e.g. CsvFragmentScanOptions).