Hi all, first of all thanks for the great work, it has been noticed in recent versions.
A few days ago I was recruited to work in the analysis of large surveys, what caught my attention is the use of the format *. zsav above *.sav.
Apparently this file format supports higher compression ratio and is more efficient with large databases to reduce their size on disk and be faster to compress-decompress to create a ZIP file (or other format) with a *.sav file .
This file type is very recent, included in SPSS version 21 and improved in the current version 22.
Personally, I can tell that the file type is very efficient in production environments (using large databases and powerful hardware).
It would be interesting to PSPP support this file type in the future.
Hugo Valencia
note: I have tried to find information about the file specification, but I have not found much (maybe I did not know where to look), so I attached a sample file in that format created with SPSS 21 converting one of the sample files included in PSPP.
physiology.zsav