vasi/pixz — pull request #1 by jlrobins (2011-10-14 14:29:38+00:00)
Title: Adds cmdline argument to cap the max # of worker threads ...

Arg -p N will limit the max number of threads / processors to
use. If left unspecified, will default to the number available
on the machine. If specified greater than that available, will
croak.

We're aiming to use pixz to compress postgres dumps performed on the same machine pixz is run on (replacing pbzip2), so need to reserve one core for running pg_dump / the postgres backend itself. If pixz uses all cores, then dump times take longer.

Thanks for writing this tool --- we're seeing ~30% improvement in compression over pbzip2. pixz seems far more memory hungry though, but we happen to have the RAM to support it.