# xan partition ```txt Partition the given CSV data into chunks based on the values of a column. The files are written to the output directory with filenames based on the values in the partition column and the `--filename` flag. By default, this command will consider it works in a case-insensitive filesystem (e.g. on macOS). This can have an impact on the names of the create files. If you know beforehand that your filesystem is case-sensitive and want filenames to be better aligned with the original values use the -C/--case-sensitive flag. Note that most operating systems avoid opening more than 1024 files at once, so if you know the cardinality of the partitioned column is very high, please sort the file on this column beforehand and use the -S/--sorted flag. Usage: xan partition [options] [] xan partition --help partition options: -O, --out-dir Where to write the chunks. Defaults to current working directory. -f, --filename A filename template to use when constructing the names of the output files. The string '{}' will be replaced by a value based on the value of the field, but sanitized for shell safety. [default: {}.csv] -p, --prefix-length Truncate the partition column after the specified number of bytes when creating the output file. -S, --sorted Use this flag if you know the file is sorted on the partition column in advance, so the command can run faster and with less memory and resources opened. --drop Drop the partition column from results. -C, --case-sensitive Don't perform case normalization to assess whether a new file has to be created when seeing a new value. Only use on case-sensitive filesystems or this can have adverse effects! Common options: -h, --help Display this message -n, --no-headers When set, the first row will NOT be interpreted as column names. Otherwise, the first row will appear in all chunks as the header row. -d, --delimiter The field delimiter for reading CSV data. Must be a single character. ```