https://code.jsoftware.com/wiki/Jd/Overview https://code.jsoftware.com/wiki/Jd/Overview Jd only packs int vectors, though. So if you're hoping for string compr

https://code.jsoftware.com/wiki/Jd/Overview https://code.jsoftware.com/wiki/Jd/Overview Jd only packs int vectors, though. So if you're hoping for string compression then I don't know of any free solution. Jd heavily leverages SIMD and mmap. Larger-than RAM columns can be easily processed by ftable. I use Jd for data wrangling before making models in R. Of course, the J language is not for the faint of heart but it's really well-suited to the task.