Re: design for parallel backup

On Wed, Apr 22, 2020 at 3:03 PM Andres Freund <andres@anarazel.de> wrote:
> The 7zip format, perhaps. Does have format level support to address what
> we were discussing earlier: "Support for solid compression, where
> multiple files of like type are compressed within a single stream, in
> order to exploit the combined redundancy inherent in similar files.".

I think that might not be a great choice. One potential problem is
that according to https://www.7-zip.org/license.txt the license is
partly LGPL, partly three-clause BSD with an advertising clause, and
partly some strange mostly-free thing with reverse-engineering
restrictions. That sounds pretty unappealing to me as a key dependency
for core technology. It also seems like it's mostly a Windows thing.
p7zip, the "port of the command line version of 7-Zip to Linux/Posix",
last released a new version in 2016. I therefore think that there is
room to question how well supported this is all going to be on the
systems where most of us work all day.

-- 
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company