Magnus Hagander <magnus@hagander.net> writes:
> Yeah, that is a clear advantage of that method. Didn't read up on pax
> format backwards compatibility, does it have some trick to achieve
> something similar?
I didn't read the fine print but it sounded like the extended header
would look like a separate file entry to a non-aware tar implementation,
which would write it out as a file and then get totally confused when
the length specified in the overlength file's entry didn't match the
amount of data following. So it's a nice solution for some properties
but doesn't fail-soft for file length. Not clear that there's any way
to achieve that though.
Another thought is we could make pg_basebackup simply skip any files that
exceed RELSEG_SIZE, on the principle that you don't really need/want
enormous log files to get copied anyhow. We'd still need the pax
extension if the user had configured large RELSEG_SIZE, but having a
compatible tar could be documented as a requirement of doing that.
regards, tom lane