--partition-by

Split a file into one output file per distinct value of a column, written into a directory. The input file is never modified.

octa --partition-by COL --out-dir DIR FILE [--partition-format EXT]

--out-dir is required (created if absent). --partition-format sets the output extension without the dot (e.g. csv, parquet); it defaults to the source file's extension.

How it works

Octa writes one file per distinct value of COL, named after the value. Partitioning a sales table by region produces North.csv, South.csv, and so on. A one-line summary is printed to stderr.

Examples

octa --partition-by region --out-dir ./by_region sales.csv
octa --partition-by year --out-dir ./by_year sales.parquet --partition-format parquet

See also

• Partition by Column (GUI) and the partition_table MCP tool.