Re: pg_waldump: support decoding of WAL inside tarfile - Mailing list pgsql-hackers

Thomas Munro <thomas.munro@gmail.com> writes:
> On Sun, Mar 29, 2026 at 11:37 AM Tom Lane <tgl@sss.pgh.pa.us> wrote:
>> It looks like to make this test stable on modern FreeBSD,
>> we need to see if tar accepts --no-read-sparse and use that
>> switch if so.

> Yeah.  Here's my attempt at perl.

Andrew might have some stylistic suggestions, but this looks
plausible to me.

> I think your Mac probably has a similar tar program BTW... but apfs
> probably doesn't go around making holes visible to lseek()
> automatically or at least as eagerly as my ZFS system.

Interesting ... on my Tahoe laptop, I see

$ tar --version
bsdtar 3.5.3 - libarchive 3.7.4 zlib/1.2.12 liblzma/5.4.3 bz2lib/1.0.8 

There is nothing in "tar --help" about sparse files, but
experimentation shows that it accepts --[no-]read-sparse.
Can't easily tell if the switch actually does anything.

            regards, tom lane